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- Only what is necessary: The use of technology in cycling and concerns with
its selection and use
Authors: Alejandro Javaloyes, Manuel Mateo-March
Pages: 1 - 2
PubDate: 2022-12-31
DOI: 10.28985/1322.jsc.16
Issue No: Vol. 11, No. 3 (2022)
- List of reviewers 2022
Authors: José Ramón Lillo-Beviá
Pages: 85 - 85
PubDate: 2022-12-30
Issue No: Vol. 11, No. 3 (2022)
- Relationship Between Isometric Peak Force and Maximal Sprinting in Elite
Track Cyclists
Authors: Greg Lewandowski
Abstract: Relationship Between Isometric Peak Force and Maximal Sprinting in Elite Track Cyclists Greg Lewandowski 1,2, Stephen McMullan 1,2 1Canadian Sport Institute Ontario, 2Cycling Canada Keywords: Isometric, Strength, Force, Torque, Power, Cycling, Sprint Introduction Isometric strength tests have been shown to provide valuable information on force-time characteristics in various sporting movements, including running, cycling and jumping (Kordi et al., 2017, 2020; Lum et al., 2020). There is a growing interest in monitoring off-bike isometric strength levels and examining their relationship with bike-specific metrics. In particular, it has been found that isometric strength measured on an adapted cycling ergometer is a predictor of maximal torque and peak power (Kordi et al., 2017, 2020). However, what is less known is the relationship between angle-specific isometric force-time characteristics measured using a strain gauge instrument fixed on a leg press and sprint cycling (6 sec maximal sprint) performance. The purpose of this research was to investigate the relationship between angle specific isometric strength and cycling specific metrics peak power and torque. We hypothesized that there would be a positive relationship with the ability to produce force in an isometric position and the ability to produce torque and power on a cycling ergometer. We propose that this setup would enable practitioners to track strength levels without requiring cycling-specific equipment and implement joint angle-specific isometric training in the weight room. Such information could help improve the effectiveness of strength training programs for cyclists. Participants Eleven elite (McKay et al. 2021) track cyclists (n=11; 3 females, 8 males), composed of six track sprint and five track endurance athletes (mean ± SD: age: 24.1 ± 3.5 yrs, body mass 82.3 ± 12.6 kg). Methodology The athletes completed two sessions: 1 sprint session on a SRM cycle ergometer and 1 isometric strength session. Both sessions were completed on the same day. Ergometer Sprint Testing Maximal sprint testing was conducted on an SRM cycle ergometer (Julich, Germany) equipped with a dynamically calibrated scientific version SRM power meter (Gardener et al., 2004). The warm-up preceding the maximal sprint test consisted of athletes performing 15 minutes of self-directed cycling, making sure athletes did one near maximal sprint within the warm-up. Immediately after the athletes performed their warm-up, athletes were instructed to complete two maximal 6-second sprints from a full stop position while seated on the SRM cycle ergometer. Each cyclist was fitted with equipment of similar geometry (e.g., seat height, seat setback, bar height, crank length) to their track bicycles used in training and racing. Data were recorded at 5 Hz, generating values representing one-revolution average (MacIntosh et al. 2004). The relationship between torque and cadence was established through a linear regression, as previously outlined (Gardner et al., 2007). Isometric Leg Press Set Up Isometric testing via a Mark-10 strain gauge attached to the leg press with a chain was performed 15 mins post sprint testing. Cyclists sat on the leg press with their foot placed firmly on the plate and the knee angle set to approximately 90° using a manual goniometer. A seatbelt was used to secure their hips, and each athlete completed a 50% maximal effort before starting the trial efforts. Starting with the right leg, athletes built up to a maximal effort for 4-5 seconds to avoid any countermovement. Athletes took a 60-second break between within-leg efforts and a 2-minute passive rest before the process was repeated on the left leg. Peak force (N) was recorded for each trial, and the average between the effort of both legs was used for analysis. It should be noted that all athletes had at least 1 prior session completing strength testing on the isometric leg press with the current set-up. Statistical Analysis The isometric leg press reliability was tested using the guidelines recommended by Weir (2005). A 2-way repeated-measures ANOVA was conducted to measure between trial reliability and separate the variance caused by systematic error versus random error, and no systemic error was observed between the isometric leg press trials (p < .05). The intraclass correlation coefficient was calculated using the 3,1 model (Shrout & Fleiss, 1979) and found to be 0.99 (95% CI: 0.916, 0.999), indicating good reliability. Pearson correlations were conducted to evaluate the relationships between peak forces in isometric tests, peak power data, and peak torque data. Results Peak force (399.32 ± 144.18 N) from cyclists’ isometric strength tests were significantly correlated with peak power (1482.55 ± 368.30 watts; r = .76, p = .007) and torque (236.00 ± 53.82 N×m; r = 0.79, p < .004) for seated sprint efforts (see Figure 1). Figure 1. Scatterplots depicting correlations between isometric force and peak power (left panel) as well as isometric force and torque (right panel). The shaded grey areas represent 95% confidence intervals. Discussion The significant correlations suggest that peak force in a single-leg isometric press can predict torque and peak power characteristics during a maximal sprint on an SRM cycling ergometer. This provides strength coaches with an alternative way to monitor athletes and provides insight into their strength levels as it relates to cycling performance without using custom-built cycling er...
Issue No: Vol. 11, No. 3
- Experimental validation of a method for virtual testing of bike settings
Authors: VOIRY
Abstract: Based on our previous works, we propose a method for virtual testing of bike settings. This allows the biomechanical and aerodynamic properties of a bike setting to be assessed without having to test it in real life. We also perform an experimental validation of the method by comparing measured and simulated values of different indicators: the frontal area, the maximum knee flexion, the maximum knee extension, the hip angle closed and the hip angle open.
Issue No: Vol. 11, No. 3
- Modelling Human Endurance: Power laws vs Critical power
Authors: Jonah Drake, Axel Finke, Richard Ferguson
Abstract: The power–duration relationship describes the time to exhaustion for exercise at different intensities. It is generally believed to be a “fundamental bioenergetic property of living systems” that this relationship is hyperbolic. Indeed, the critical- power model which formalises this belief is the dominant tool for studying endurance exercise, e.g. in cycling, running, rowing, or swimming. However, this model is now the focus of a heated debate because it unrealistically represents efforts that are short (< 2 minutes) or long (> 15 minutes). We contribute to this debate by demonstrating that the power--duration relationship is not hyperbolic (and thus cannot be adequately described by a “critical power’’ parameter). Rather, the power–duration relationship is more adequately represented by an alternative power-law model. In particular, the oftenobserved good fit of the critical-power model to exercise durations between 2 and 15 minutes should not be taken as proof that the power–duration relationship is hyperbolic. Rather, in this range, a hyperbolic function just happens to approximate a power law fairly well. Additionally, we show that the power-law model sheds light on the strengths and limitations of many popular rules of thumb for performance prediction such as Jack Daniel’s “VDOT” tables in running and FTP in cycling. For instance, for the latter, it explains why the 95-% rule for estimating a cyclist’s 60-minute power output from a 20-minute effort is too optimistic.
Issue No: Vol. 11, No. 3
- Performance of under 23 and elite mountain bikers during cross-country
short track event.
Authors: Rhaí André Arriel, Anderson Meireles, Hiago Souza, Moacir Marocolo
Abstract: The aim of this study was to investigate the distribution of speed and performance of professional cross-country cyclists on different technical and non-technical sections during a cross-country short track (XCC) mountain biking (MTB) event. Twenty male professional cross-country cyclists (25.9 ± 5.4 years) performed six laps of an XCC International Mountain Bike Cup. In addition to categories [Under 23 (n = 8) and Elite (n = 12)], cyclists were divided into three different groups according to their overall race completion time, being categorized as top (n = 6), middle (n = 8) and bottom (n = 6) placed finishers (race time groups). Average speed (by lap and in five different track sections) was analyzed according to all athletes, categories and race time group. Athletes in general and both categories adopted a positive pacing. Top cyclists adopted a “W-shaped” pacing, while middle and bottom cyclists adopted a positive and reverse J-shaped pacing profile, respectively. Regarding track sections performance, no difference was found between categories (p > 0.05). Furthermore, top cyclists were 18.8% (p < 0.05), 6.7% (p < 0.05) and 4.1% (p < 0.05) faster than bottom cyclists on sustained non-technical uphill, technical short uphill/downhill section and non-technical downhill sections of the track, respectively. The results show that majority of athletes adopted a positive pacing profile during XCC, but the better XCC performance was associated with a “W-shaped” pacing profile and higher performance mainly on sustained non-technical uphill.
Issue No: Vol. 11, No. 3
- Athlete Preparation for Consecutive Team Pursuit World Record Performances
Authors: Antony Stadnyk
Abstract:
Introduction Performances in the 4000-metre team pursuit have improved rapidly in recent years. However, limited evidence exists of the training characteristics of track cyclists in preparation for this event. Along with technological advances, changes in physical, mental, tactical, and technical capacities have likely contributed to the improved performances. Understanding the training periodisation eliciting the desired adaptations to optimise performance on race day is of great interest to coaches, practitioners, and athletes. In this exploratory study, we compared the 3-month preparation phases prior to world-record performances to identify similarities and differences in the physical preparation of an elite team pursuit squad.
Materials and Methods Subjects — Five male track endurance cyclists — members of the Australian Cycling Team during the 2018 and 2019 seasons — participated in the study. Research approval was granted by the national federation prior to athletes providing informed consent. The study was approved by the University of Technology Sydney Human Research Ethics Committee and complied with the Declaration of Helsinki. Design — The exploratory study design analysed athlete testing, training, and performance data in the 13-week period prior to each world-record performance (WR1, 05 Apr 2018; WR2, 28 Feb 2019). Methodology — Training diaries were exported from TrainingPeaks™ (CO, USA) for systematic inspection and coding in Excel 2016 (Microsoft, WA, USA). Individual session files were analysed in Golden Cheetah v3.5 (GPL v2 open-source license, UK) and exported as 1-Hz raw data for grouped analyses and modelling in R v4.0.2 (R Core Team, 2021). Training intensity distributions were calculated using lab-based test data for traditional (LIT [below LT1] < MIT < HIT [above LT2]) and team pursuit race-relative (Follow [Wheels 2-4] < Average [W1-4] < Lead [W1]) thresholds. Statistical Analysis — Week-to-week intensity distribution and load accumulation for power and torque were calculated. Data are presented as mean ± SD. Where appropriate, time-matched paired t-tests were performed to assess between-season differences.
Results Pyramidal intensity distributions were observed weekly for power output with 81 ± 6% and 81 ± 4% of total time spent below LT1 (LIT) in the 2018 and 2019 seasons, respectively (Figure 1). Similar average weekly volumes were observed at moderate (13 ± 5% and 12 ± 3%) and high (6 ± 3% and 6 ± 3%) intensities between seasons. Athletes accumulated greater proportions of training above the respective world-record race-relevant torque in the second season (Figure 2), with 6.2 ± 2.3% (vs 3.2 ± 1.5%) spent above WR Lead torque demands. Greater variation in gear and pace evolution was observed during training sessions in the second season as the team integrated gym- and bike-based strength development toward their race target pace.
Discussion This was the first study to compare the training intensity distribution and load accumulation of an elite team pursuit cycling squad in the lead-up to two successive world-record performances. Analyses found a pyramidal intensity distribution was common in the athletes' training between seasons, with most bike-specific training performed at low intensities, with only a small amount at high intensity. However, a greater volume of training was accumulated at intensities above race-relevant (i.e., WR Lead, Average, and Follow) power and torque demands. In the second season, training emphasis was placed on continued development of peak torque and rate of force development, as well as tolerance of higher gear sizes and the associated neuromuscular stress. Modifications to track training sessions allowed the athletes to accumulate greater high-intensity load while still getting necessary race-distance volume. These manipulations of work, recovery, gear sizing and pace, allowed for specific targeting of metabolic adaptations within race-specific efforts.
Practical Applications. Elite team pursuit cyclists can develop performance in a track-focused program supported by well-structured road-based volume. Integration of bike- and gym-based force development can allow athletes to produce and tolerate the neuromuscular loads required for world-record performances. Increases in torque production and tolerance through the use of larger gear sizes, along with variations in pace, and manipulation of work and recovery during track sessions may contribute to improved team pursuit performance. These findings may be beneficial to coaches, athletes, and practitioners in training planning and the development of team pursuit cyclists.
Issue No: Vol. 11, No. 3
- Coconut water; a sports drink alternative'
Authors: Leo Bell
Abstract: Coconut water is used in replacement of sports drinks for hydration during endurance cycling, however evidence to support it is limited. This study determined if drinking coconut water compared to a sports drink altered cycling performance and physiology. In a randomized cross-over trial, 19 experienced male (n=15) and female (n=4) cyclists (age 30±9 years, body mass 79±11 kg, V̇O2 peak 55±8 mL.kg-1.min-1) completed two experimental trials consuming either a commercially available sports drink or iso-calorific coconut water during 90 minutes of sub-maximal cycling at 70% of peak power output, followed by a simulated, variable gradient, 20-km time trial. Blood glucose, lactate, sweat loss, and heart rate were monitored throughout 90 minutes of sub-maximal cycling, as well as time trial performance (seconds) and average power (watts). A repeated measures analysis of variance and effect sizes (Cohen’s d) analysis were applied. There were no significant differences (p ≥ 0.05) between treatments for any measured physiological or performance variables. Additionally, effect size analysis showed only trivial (d ≤ 0.2) differences between treatments for all measured variables, except blood glucose, which was lower in the coconut-water trial compared to the sports drink trial (d = 0.31). Consuming coconut water has a similar effect on cycling time trial performance and physiological responses to consuming a commercially available sports drink.
Issue No: Vol. 11, No. 3
- Relationship Between Isometric Peak Force and Sprinting in Cycling
Performance within Elite Track Cyclists
Authors: Greg Lewandowski
Abstract: Relationship Between Isometric Peak Force and Sprinting in Cycling Performance within Elite Track Cyclists Greg Lewandowski 1,2, Stephen McMullan 1,2 1Canadian Sport Institute Ontario, 2Cycling Canada Keywords: Isometric, Strength, Force, Torque, Power, Cycling, Sprint Introduction Isometric strength tests have been shown to provide valuable information on force-time characteristics in various sporting movements, including running, cycling and jumping (Kordi et al., 2017, 2020; Lum et al., 2020). There is a growing interest in monitoring off-bike isometric strength levels and examining their relationship with bike-specific metrics. In particular, it has been found that isometric strength measured on an adapted cycling ergometer is a predictor of maximal torque and peak power (Kordi et al., 2017, 2020) However, the relationship between angle-specific isometric force-time characteristics measured using a strain gauge instrument fixed on a leg press and sprint cycling performance has not been thoroughly investigated. We propose that this setup would enable practitioners to track strength levels without requiring cycling-specific equipment and implement joint angle-specific isometric training in the weight room. Such information could help improve the effectiveness of strength training programs for cyclists. Subjects Eleven elite (McKay et al. 2021) track cyclists (3 female; 8 male) - six sprint and five endurance (mean ± SD age: 24.1 years ± 3.5, body mass 82.3 kg ± 12.6 kg) Methodology Ergometer Sprint Testing Maximal sprint testing was conducted on an SRM cycle ergometer (Julich, Germany) equipped with a dynamically calibrated scientific version SRM power meter (Gardener et al., 2004). To warm up for the maximal sprint test, cyclists performed 15 minutes of self-directed cycling. Next, they performed two maximal 6-second sprints from a full stop while seated. Each cyclist was fitted with equipment of similar geometry (e.g., seat height, seat setback, bar height, crank length) to their track bicycles used in training and racing. Data were recorded at 5 Hz, generating values representing one-revolution average (MacIntosh et al. 2004). Isometric Leg Press Set Up The strain gauge was attached to the leg press with a chain. Cyclists sat on the leg press with their foot placed firmly on the plate and the knee angle set to approximately 90° using a manual goniometer. A seatbelt was used to secure their hips, and each athlete completed a 50% maximal effort before starting the trial efforts. Starting with the right leg, athletes gradually built up to a maximal effort for 4-5 seconds to avoid any countermovement. Athletes took a 60-second break between efforts and a 2-minute passive rest before the process was repeated on the left leg. Peak force (N) was recorded for each trial, and the average between the effort of both legs was used for analysis. Statistical Analysis The isometric leg press test’s reliability was tested using the guidelines recommended by Weir (2005). A 2-way repeated-measures ANOVA was conducted to measure between trail reliability and separate the variance caused by systematic error versus random error, and no systemic error was observed between the isometric leg press trials (p < .05). The intraclass correlation coefficient was calculated using the 3,1 model (Shrout & Fleiss, 1979) and found to be 0.99 (95% CI: 0.916, 0.999), indicating good reliability. Pearson correlations were conducted to evaluate the relationships between peak forces in isometric tests, peak power data, and peak torque data. Results Peak force (399.32 ± 144.18 N) from cyclists’ isometric strength tests were significantly correlated with peak power (1482.55 ± 368.30 watts; r = .76, p = .007) and torque (236.00 ± 53.82 N×m; r = 0.79, p < .004) for seated sprint efforts (see Figure 1). Figure 1. Scatterplots depicting correlations between isometric force and peak power (left panel) as well as isometric force and torque (right panel). The shaded grey areas represent 95% confidence intervals. Discussion The significant correlations suggest that peak force in a single-leg isometric press can predict torque and peak power characteristics during a maximal sprint on an SRM cycling ergometer. This provides coaches with an easier way to monitor athletes and provides insight into their strength levels as it relates to cycling performance without using custom-built cycling ergometers (Kordi et al., 2020). Practical Application This protocol provides practitioners with an easy-to-administer, task-specific and safe testing tool to infer an athlete’s progress, especially when cyclists cannot access a power meter or laboratory-grade cycling ergometer and coaches need to baseline or talent identification. Practitioners can now use this information to devise isometric training protocols withing a weightroom, knowing that there is a strong relationship with the ability to produce peak power and torque. Future work is warranted to investigate the longitudinal utility of peak isometric force to assess changes in peak torque and peak power in elite track cyclists. References
Gardner, A. S., Stephens, S., Martin, D. T., Lawton, E., Lee, H., & Jenkins, D. (2004). Accuracy of SRM and power tap power monitoring systems for bicycling. Medicine & Science in Sports & Exercise, 36(7), 1252-1258. 2.Kordi, M., Folland, J. P., Goodall, S., Menzies, C., Patel,...
Issue No: Vol. 11, No. 3
- Effect of different rest intensities on time spent near maximal oxygen
uptake during a decreasing high-intensity training session – a pilot
study
Authors: Christoph Triska, Christoph Soukup, Markus Scharner, Pit Milbert, Johannes Ernst, Astrid Mathy
Abstract: n/a
Issue No: Vol. 11, No. 3
- A laboratory treadmill for simulation of road surface induced vibrations
in cycling
Authors: Jens Buder, Giuseppe Sanseverino, Stephan Odenwald, Stefan Schwanitz
Abstract: Within the framework of a systematic approach, a novel test setup for the simulation of road surface induced vibrations was developed. This can be used for various questions concerning the oscillatory system cyclist-bicycle. The innovation compared to the state of the art is the separate introduction of vibrations at the front and rear wheel while at the same time enabling a natural riding behavior during pedaling and coasting, even at higher speeds.
Issue No: Vol. 11, No. 3
- Effects of test duration on pressure distribution, pelvic stability, and
subjective perception in laboratory investigations for evaluating bicycle
saddles and seat pads
Authors: Stefan Schwanitz, Sophie Richter, Frank I. Michel
Abstract: The aim of this study was to investigate the consistency of typical evaluation characteristics used to assess seating systems in cycling for both male and female cyclists, over a ride time of up to 60 minutes. Pressure distribution, pelvic stability, and subjective perception were measured in a laboratory test using a stationary bicycle. Results showed that mean pressure load increased with the duration of the test, particularly in the first 30 minutes, leading to a decrease in overall subjective comfort. The analysis of pelvic motion yielded inconclusive findings for both genders. Based on these results, it is recommended that future tests should last at least 15 minutes per condition to obtain reliable and valid data.
Issue No: Vol. 11, No. 3
- The Introduction of a Generic Cycling Model
Authors: Christopher Brown, Toon Huysmans, Wouter Terra, Mark Thompson, David Burton
Abstract: In this research program, we have created a generic cyclist model with an open-source geometry that other researchers can use for aerodynamic investigations. A selection of 14 professional male athletes was scanned in the endurance posture, equivalent to the time-trial position. The surface geometry scans were processed and combined into one model through an averaging procedure. This procedure involved creating a base mesh and articulating it into roughly the same position. Reference landmark points are then defined on the base mesh and the 3D scans at meaningful anatomical locations. This allows aligning and non-rigidly registering the two, ensuring each scanned athlete has the same mesh connectivity. Once registered, a weighted average of surface meshes is computed to generate a generic cycling model. The weighting was adjusted to match the anthropometrics of professional cyclists competing in the 2012 London Olympics Road Race.
Issue No: Vol. 11, No. 3
- FTP in cycling: functional or fictional threshold power'
Authors: Kevin Caen
Abstract: Functional threshold power (FTP) is a very popular metric in recreational and competitive cycling to evaluate, monitor and predict performance. This “threshold” is defined as the power output that a rider can maintain for one hour and is mostly determined by calculating 95% of the mean power output performed during a 20-min time trial. The popularity of FTP mainly originates from its practical feasibility, however, the scientific basis of this concept can be questioned. In this presentation, the physiological meaning of FTP and its relationship to other threshold concepts, such as critical power and the maximal lactate steady state, will be critically evaluated. Based on the most recent insights from literature, both the advantages and disadvantages of utilizing FTP in research and practice will be delineated.
Issue No: Vol. 11, No. 3
- Continuous Glucose Monitoring of Non-Diabetic Professional Cyclists during
a Training Camp
Authors: Andrea Giorgi, Borja Martinez-Gonzalez, Maurizio Vicini, Andrea Zignoli, Kristina Skroce
Abstract: Cyclists undergo demanding efforts both in training and competition that may perturb the glucose metabolism. Recent advances in wearable technology have produced a variety of devices which can be used to monitor biometric parameters in athletes like interstitial glucose. The aim of this study was to describe daily glucose fluctuations using a continuous glucose monitoring device in non-diabetic professional cyclists during a training camp. Values showed stability of interstitial glucose concentration and a relatively low occurrence of overnight hypoglycemia. These results suggest that the athletes maintained adequate glucose levels and control across the training camp.
Issue No: Vol. 11, No. 3
- Predicting performance in sub-10s f200 m male track sprint cyclists
Authors: Thomas Wackwitz
Abstract: Maximal power output (Pmax) and the ability to sustain power output close to Pmax are primary determinants of track sprint cycling performance. Given Pmax is achieved at a specific optimal cadence (Fopt) the importance of gear selection is paramount. To optimise gear selection for a specific event, individualised fatigue rates (i.e., fatigue rate per maximal pedal stroke) and field-derived Torque- & Power-Cadence profiles can be used in combination with physics-based model of track cycling. The aim of this investigation was to produce a model of track sprint cycling that can accurately predict performance times of the f200-m. The model utilised mechanical profiles derived from laboratory and field testing as the input variable to optimise f200-m gear selection and performance in elite and world-class track sprint cyclists. Six elite male track-sprint cyclists (Pmax = 2146 ± 423W) completed two testing sessions to identify Torque-Cadence (T-C) and Power-Cadence (P-C) profiles, while fatigue rates were identified during maximal sprints performed at Fopt. The P-C and fatigue profiles were utilised to predict power output during a f200-m event and, in conjunction with a physics-based model of track cycling, predict performance times. This physics model was also utilised to simulate the f200-m performance with different gear ratios. The gear ratio that resulted in the fastest f200-m time was deemed to be theoretically optimal for each athlete. There was no significant difference between the modelled (10.23 ± 0.60s) and actual (10.23 ± 0.53s) f200-m times (p=0.9254). The model predicted that three of the athletes could theoretically improve f200-m performance by increasing the gear ratio, while three could theoretically benefit from a lower gear ratio. P-C and fatigue rate profiles in combination with a physics-based model of track cycling can be used to accurately predict f200-m times.
Issue No: Vol. 11, No. 3
- FTP in cycling: functional or fictional threshold power'
Authors: Kevin Caen
Abstract: Functional threshold power (FTP) is a very popular metric in recreational and competitive cycling to evaluate, monitor and predict performance. This “threshold” is defined as the power output that a rider can maintain for one hour and is mostly determined by calculating 95% of the mean power output performed during a 20-min time trial. The popularity of FTP mainly originates from its practical feasibility, however, the scientific basis of this concept can be questioned. In this presentation, the physiological meaning of FTP and its relationship to other threshold concepts, such as critical power and the maximal lactate steady state, will be critically evaluated. Based on the most recent insights from literature, both the advantages and disadvantages of utilizing FTP in research and practice will be delineated.
Issue No: Vol. 11, No. 3
- Longitudinal bending stiffness of cycling footwear - What is stiff
enough'
Authors: Stefan Litzenberger
Abstract: To investigate the influence of a cycling shoe’s longitudinal bending stiffness on the kinematics of the cyclist’s foot, three identical leisure-cycling shoes for flat pedals with different longitudinal bending stiffness were tested during indoor trials with twelve male subjects riding at five intensities in seated and standing cycling, respectively. Using an infrared-based 3D motion capture system and power output measurement with a crank-based power meter it was shown that power output does not differ significantly between shoes with different sole stiffness, that metatarsophalangeal angle between forefoot and rearfoot is increasing with increasing power and mostly decreasing with increasing bending stiffness of the shoe and that the pedal angle over crank-cycle shows individual differences that can be clustered in three types. Ultimately it can be said that Ethylenvinylacetat (EVA) inlays show excessive bending whereas there is only a small difference between nylon and nylon-carbon inlays.
Issue No: Vol. 11, No. 3
- Working title: Early professionalism - establishing a platform for optimal
performance
Authors: Deena Blacking
Abstract: OBJECTIVE In recent years, women’s elite cycling has made several sizeable steps towards professionalisation (1). However, there are still many disparities and challenges which impede the creation of an optimal environment for the highest levels of sporting performance in the women’s peloton. Further, there is relatively little research and information available about women’s professional cycling. This paper presents the findings of 9 separate surveys of the women’s professional peloton which span the period 2017 to 2022. The surveys make enquiries into the working conditions and experiences of professional female cyclists. The information gathered via these surveys is unique, informative and provides insight into the evolution and current state of the women’s professional peloton. This is the first presentation of all survey results. DESIGN Nine surveys (see Table 1) were conducted by, or on behalf of The Cyclists’ Alliance (TCA), an independent labour union for women in professional cycling which was founded in 2017 by professional female road cyclists following the results of the first survey. Topics surveyed included: salaries; the need for a second job; number of years racing; race days; education level and (concurrent) study, and the use of agents and legal assistance. The surveys also gathered views and testaments about psycho-socio cultural questions and experiences in the women’s professional peloton, including perceptions of safety, happiness and clarity of role expectations. TABLE 1 Survey: year and number of respondents Survey No. Year survey conducted Number of unique respondents 01 2017 196 02 2017 126 03 2018 112 04 2019 128 05 2020 98 06 2021 97 07 2021 74 08 2021 76 09 2022 124 RESULTS The results tend to show a general growth in professionalisation, evidenced by increases in wages and an increased use of agents and legal assistance. However, data also suggests growing disparity across the peloton between World Tour and Continental teams. For example, many riders in Continental teams that compete in World Tour races receive less than a living wage or no salary at all. The most recent survey (2022) revealed that the primary reason for ‘leaving the sport early’ is ‘financial reasons’. Qualitative responses regarding team culture and working conditions reveal some positive trends (such as an increase in reporting on ‘happiness’ between 2021 and 2022). However, riders in all levels of team continue to experience situations, scenarios and working conditions which are not conducive to performance. In some cases, riders reported unsafe practices, such as pressure to race when concussed. It is the intention that the findings presented in this paper can provide a platform for future research and development of the women’s professional peloton. (1) van Erp, T. (2019). The Development of Women’s Professional Cycling. Journal of Science and Cycling, 8(3), 1-2. https://doi.org/10.28985/1920.jsc.01
Issue No: Vol. 11, No. 3
- Physiological Characteristics Associated with W′ and W′bal Used During
Intermittent Exercise Task to Failure.
Authors: Alex Welburn, Richard Ferguson , Stephen Bailey, Charles Pugh
Abstract: The critical power (CP) and W′ concept has become more integrated within applied cycling performance assessment. Both parameters can be tested for in the laboratory and field and have thus become a useful tool for coaches and athletes. The development of the Wbal concept allows us to mathematically model the depletion and recovery of W′ (Skiba et al., 2012, Skiba and Clarke, 2021). When exercising above CP, there is a proposed linear utilisation of W′. When exercising below CP, W′ is reconstituted (W′rec). When W′ has been fully utilised and Wbal (the balance between utilisation and reconstitution) reaches 0, it is assumed exhaustion will occur. Despite the attention given to the underpinning physiological determinants of CP which are well established (Poole et al., 2016; Mitchell et al., 2018 and Chorley et al., 2020) the physiological determinants of W′ are not as well understood. W′ correlates with muscle volume in elite track cyclists (Kordi et al., 2021) yet there are no correlations with the muscle fibre composition (Vanhatalo et al., 2016; Mitchell et al., 2018), muscle capillarity (Mitchell et al., 2018) or mitochondrial content and function (Rogers, Ferguson et al., unpublished). It has, however, been suggested that so-called muscle typology influences W′rec following high intensity exercise (Lievens et al., 2020). Furthermore W′rec differs between intensity domains (Lievens et al., 2021) with Caen et al. (2021) concluding that W′rec following exhaustion is based on parameters of aerobic fitness due to the faster onset of V̇O2 kinetics, and thus W′rec has been demonstrated to follow a two-phased exponential time course. Despite this, more work is needed to understand the factors influencing W′ and W′rec so we can have greater confidence in its use as a performance and training tool. As part of a wider PhD research project the associations between physiological performance characteristics, W′ and W′rec were examined. The initial aim of the study was to assess the relationship between physiological performance characteristics and W′. The second aim was to then determine which characteristics were associated with the total amount of work done above CP (W′total) during three different intermittent exercise protocols. Finally, W′rec parameters were modelled, using different Tau calculations to assess which model would predict a Wbal of 0 at exhaustion. Thirteen endurance trained cyclists (10 males, 3 females; age: 23[8] y, height; 177 [7] cm, body mass; 69.2 [8.3] kg, V̇O2max; 54.3 [11.6] mL·min-1·kg-1, MAP; 371 [70] W, PMAX 1214 [307] W, CP; 270 [49] W, W′ 20.5 [6.2] kJ, mean [SD]) were recruited for this laboratory-based investigation. Participants attended the laboratory on seven separate occasions for the determination of V̇O2max and maximal aerobic power (MAP), lactate threshold (first LT [LT1], baseline + 0.4 mMol.L-1); second LT [LT2, fixed blood lactate concentration of 4 mMol·L-1), CP and W′ (3 and 12-minute method, Simpson and Kordi, 2017; peak lactate [Bla-]Peak and lactate clearance rate [BLa-]CLR and maximal sprint power ([Pmax; peak 1s power). All performance tests were performed on the participants own racing bicycle attached to a Wahoo Kickr with self-selected power chosen for the CP trials and main trials completed in ERG mode. Three intermittent exercise trials were also completed. Intervals were performed at a power output equivalent to the calculated 6-minute power (P6) + 50% of the difference between P6 and CP. Recovery power was 50% of LT1. The three intermittent trial protocols involved: 3 x 60s efforts with 30s recovery proceeded by a sustained time to exhaustion (TTE); 3 x 20s with 10s recovery proceeded by a TTE; continued 20s efforts with 10s recovery until exhaustion, examining total work done above CP (W′total). Different W′bal Tau calculations were used (Skiba at al., 2012; Bartram et al., 2018 and Pugh et al., 2021 (Reg & Nat). Individualised Tau (TauINDV) using a single value to give Wbal 0 at the point of task failure were also assessed. To establish relationship between W′, W′total, and TauINDV, Person′s product-moment correlations were performed. W′ was associated with Pmax (r=.822 p=<0.001), MAP (r=.735, P=0.004), peak [BLa-] (r=.645, p= 0.017) and V̇O2max (r=.645, p=0.026). W′total was correlated with CP·kg-1 (r=.766, p=0.002), LT1·kg-1 (r=.771, p=0.006) and PMax·kg-1 (r=.792, p=0.001). W′bal at the end of the 20:10 until exhaustion trial using the following Tau values were, Skiba, -20.3 [12.6] kJ; Bartram, 8 [3.5] kJ; Pugh Nat, -3.8 [4.3] kJ; and Pugh Reg, -2.6 [4.7]. TauINDV was correlated with CP·kg-1 (r=0.696 p=0.012), and there tended to be a correlation with LT1·kg-1 (r=0.564, p=0.056). These data suggest that W′ has many contributing factors, with Pmax and MAP being of particular importance, likely reflecting the extent of muscle mass usually associated with high absolute power outputs. We also demonstrate that CP, LT1 and Pmax normalised to body mass are important factors for W′total during severe intensity intermittent exercise, likel...
DOI: 10.1123/ijspp.2017-0034. caen kevin gil bourgois charles dauwe laura blancquaert kobe vermeire eline
Issue No: Vol. 11, No. 3
- Tracking towards Paris: Investigating the bioenergetics of increasing
cycling workloads with bilateral crank differences - research into
practice
Authors: Chantelle du Plessis
Abstract: It is known that strength, exercise tolerance, physiological capacities, motor coordination and control may be reduced in cerebral palsy athletes due to muscle weakness, joint range of motion limitations and spasticity, when compared to their able-bodied counterparts (Lepretre et al., 2012, Fletcher et al., 2021). Consequently, investigating an individual’s physiological and biomechanical profile is warranted to provide a fundamental understanding of their potentially unique energetic capacities and movement patterns. Such information could be used to develop individualised training programs and racing strategies, especially within an elite para-cycling environment. Initial observations within our high-performance institute of an elite female para-cyclist, who has cerebral palsy, have indicated bilateral differences in strength and coordination in her upper and lower body, with the right side more affected. As a result, the support team’s focus has been to optimise bicycle position, including to investigate different crank lengths, to potentially minimise, and importantly, improve bilateral differences. Therefore, an investigation is underway that uses the cycling energetic testing framework already developed as part of the institute’s research activities to assess the physiological and biomechanical profile of this world-class female para-cyclist, and to understand the potential effects on this profile when manipulating the crank lengths. During cycling, the power delivered to the bicycle cranks is a result of the sum of the ankle, knee and hip joint-specific powers transferred through the limb-segments (van Ingen Schenau et al., 1990); with the hip extension power shown to dominate through a range of increasing workloads from 250 W to short, maximal sprints in able-bodied cyclists (Elmer et al., 2011). Moreover, although most of the existing research has concluded that crank lengths used within the practical limits (165-175 mm) do not impact the athlete’s ability to produce peak power during short, maximal sprinting (Martin and Spirduso, 2001), joint-specific power contributions may shift towards the larger proximal hip joint (Barratt et al., 2011, 2016) and may influence longer duration efforts differently. We do not currently know whether the right-limb asymmetry of our female para-cyclist influences her joint-level biomechanics, nor whether her hip joint, in particular, is affected by crank length changes. Overall, any change in joint level contribution may impact muscle contributions surrounding these joints. This may influence the energy cost of the working muscles, and the total, whole-body, energy cost, which could result in an increase the rate of performance fatigue. Alternatively, it is possible that a movement pattern strategy could involve shifting the joint contributions to recruit muscles that are able to do more work before they fatigue; possibly minimising whole-body- physiological cost and delaying the onset of fatigue. In line with this reasoning, the aim of this analysis is to enhance this fundamental understanding of the energetic profile of our female para-cyclist to explore potential opportunities for performance improvement in upcoming key benchmark events. The data collection procedures involved the athlete cycling on a Lode Excalibur Sport cycle ergometer where left and right pedal force application were measured through instrumented bicycle cranks, 3-D motion was captured through Vicon Motion Analysis system, and muscle activation patterns were investigated through EMG. In addition, oxygen consumption and blood lactate concentration were measured to assess the physiological cost of movement. Data analysis of the key parameters will be completed, and final results will be presented at the conference.
Issue No: Vol. 11, No. 3
- The Correlation Between Pedaling Rate and Gross Efficiency of Road Bike
Cycling
Authors: Liang Cheng Huang, Tsang Hai Huang, Ying Ju Chen, Ya Han Chang, Chin Lai Huang
Abstract: : To investigate the relation between the gross efficiency (GE) and the pedaling cadence (rpm) under different intensities of cycling. Methods: Ten amateur male cyclists were recruited. Each participant completed five tests, which were the maximal incremental test, functional threshold power (FTP) test and three multi-cadence ride tests. The three multi-cadence ride tests were conducted under different intensities of personal 90% FTP, 100% FTP and 105% FTP. A repeated measures 2-way ANOVA was adopted to compare the effects of intensity and gear ratio on GE. Pearson’s correlation was conducted to investigate the relation between gross efficiency and cadence (rpm). Results: For the main effect of intensity, no statistically significant difference was shown. For the main effect of gear ratio, GE’s values among gear 1 to gear 4 or 5 didn’t show significant difference while the values in gear 6 or gear 7 mostly demonstrated significant difference to other gear ratio. By splitting the data according to cadence (e.g. 80, 85, 90 and 95 rpm), the original data of GE versus rpm would be divided into two groups. Through linear regression, the rpm data of 90 and lower showed no significant correlation with GE. Conversely, the rpm data higher than 90 were negatively correlated with GE. In the current study, we found that there is a turning point of rpm corresponding to a drop of exercise efficiency. And it seems not a certain cadence, but a range of cadence demonstrates an equivalent and personal optimal GE. Whether the cyclists should pedal at a rpm close to the turning point is valuable for further study. Keywords: metabolic energy expenditure, cadence, work rate,
Issue No: Vol. 11, No. 3
- Reliability and Sensitivity of the Notio Device and Aer-oscale Service to
Quantify Cyclists' Drag Coefficients in Outdoor Conditions
Authors: Thomas Lambolais, Antoine Bruez, Thibault Dugenne, Quentin Caillou, Thibaut Peron, Stéphane Perrey
Abstract: Notio is a device based on a wind sensor which offers estimates of the CdA (drag coefficient multiplied by the area) of the pair cyclist and bike. Notio is used with specific analysis software, which computes CdA estimates after a ride. The Aeroscale Company proposes a half-day service with their own wind sensor and experimental protocol, to also deliver estimates of the CdA. In both cases, the main objective of a wind sensor is to give estimates in outdoor conditions. The Aeroscale specificity is that all experiments are done without any power sensor, in freewheel. In our study, we experimented Notio device and software as well as Aeroscale Service through an incremental protocol with increasing disks, which led us to obtain sensitivity measures of 4.5% for Notio and 0.5% for Aeroscale, with a reliability of 8% for Notio and 1% for Aeroscale.
Issue No: Vol. 11, No. 3
- A short self-paced submaximal test to monitor endurance cycling fitness
Authors: Jules Cusson-Fradet, Frédéric Domingue , Calude Lajoie
Abstract: Introduction Monitoring the cyclists’ responses to training is important for optimizing training and improving cycling performance (Galán-Rioja, Gonzalez-Ravé, González-Mohíno, & Seiler, 2023; Jeffries et al., 2021). However, this process can be costly and time-consuming. Submaximal fitness tests provide a practical alternative to traditional maximal tests, allowing the monitoring of training effects while minimizing disruptions to the athlete's training and competition schedule (Shushan et al., 2022). Recently, Sangan, Hopker, Davison, & McLaren (2021) proposed the self-paced submaximal run test (SRTRPE) as a more practical form of the running version of the Lamberts and Lambert submaximal cycling test (LSCT) (Lamberts, Swart, Noakes, & Lambert, 2011). The LCST measures cycling power output (w) or running velocity (v) and ratings of perceived effort (RPE) during two 6-minute stages and one 3-minute stage of increasing intensity, which are determined by a fixed percentage of the maximum heart rate (Lamberts et al., 2011; Vesterinen et al., 2016). In contrast, the SRTRPE monitors v and heart rate (HRex) during three 3-minute stages prescribed by RPE 10, 13, and 17 (Sangan et al., 2021). The self-paced nature of the SRTRPE makes it potentially more specific to the pacing demands of competition and, more importantly, less cumbersome since there is no requirement to collect and to store RPE data for later analysis, nor to do a prior maximal testing to establish the relative intensity of each stage. Furthermore, standardizing intensity by RPE could provide a better insight into the individual's responses to endurance training by reflecting more accurately individual differences in the exercise intensity domains (Iannetta et al., 2020; Seip, Snead, Pierce, Stein, & Weltman, 1991). Sangan et al. (2021) reported promising findings showing that v, at all stages of the SRTRPE, was largely correlated with aerobic fitness parameters such as maximal oxygen uptake (VO2max), v at VO2max (vVO2max), and v at lactate threshold 2 (vLT2). Moreover, test retest analysis showed acceptable reliability with coefficients of variation between 2.5% and 5.6% for v and HRex at all stages (Sangan et al., 2021). Given the supportive findings and potential benefits of a self-paced design, the aim of our study was to evaluate the feasibility of a cycling-specific adaptation of the SRTRPE protocol. The modified protocol incorporates the latest research on RPE and is tailored towards the specific requirements of road cycling (Ebert, Martin, Stephens, & Withers, 2006; Lopes, Pereira, & Silva, 2022). The self-paced submaximal cycling test (SCTRPE) measures w and HRex responses during three 2-minute stages using Borg's CR100 scale (RPE Moderate, Hard, Very Hard) and evaluates neuromuscular function with one second peak power (wsprint) and post-exercise heart rate recovery (HRR). Materials and Methods Twenty-three trained to highly trained (29.6 ± 9.2 y, 72.7 ± 9.7 kg, VO2peak 65.6 ± 7.1 ml∙kg-1∙min-1) endurance cyclists (including 3 females) received standardized RPE instructions and anchoring procedures. Then, they underwent the first trial of the SCTRPE. They also performed three 6-second maximal sprints and a graded exercise test (GXT) to determine their maximal neuromuscular one second peak power (wMAXsprint), ventilatory thresholds (VT1, VT2), peak oxygen consumption (VO2peak), and peak power (wpeak). Within a period of 2 to 14 days, the participants completed two additional trials of the SCTRPE to evaluate the test-retest reliability of HRR, wsprint, HRex, and w at each stage of the test. Correlations were used to examine the relationship between the SCTRPE and the parameters measured during the GXT to establish convergent validity. Results Power output measured during all stages of the SCTRPE had moderate to very large correlations with the parameters measured during the GXT, ranging from .48-.85. Notably, the highest correlation (r = .85) was observed between wpeak and w at RPE Very Hard (Figure 2). The intraclass correlation coefficients (ICC3,1) for w and HRex at all stages of the SCTRPE ranged from .86-.92, indicating high to very high reliability, with typical errors (TEs) ranging from 2.7% to 7.9% (Table 1). The reliability of HRR expressed as a percentage of the peak heart rate recorded during the trial (HRR%hrpeak) and wsprint was found to be moderate and very high, respectively, with ICC3,1 value of .74 and .93, and TEs of 4.4% and 6.7% (Table 1). Conclusions The study findings suggest that the SCTRPE is a reliable and valid measure of endurance cycling fitness. The high intraclass correlation coefficients and good convergent validity with the parameters of the GXT, particularly wpeak, indicate that the SCTRPE could be an effective and practical test to monitor endurance cycling athletes’ responses to training.
Issue No: Vol. 11, No. 3
- Acute and chronic effects of training with a fixed gear on pedaling
technique
Authors: Eneko Fernández-Peña, Piero Benelli, Alexander Bertuccioli , Antonino Patti, Marco Gervasi
Abstract:
Introduction In cycling, the round pedaling technique is characterized by applying force as uniformly as possible throughout the entire pedal cycle (2). This involves applying more force in areas of the pedal stroke such as dead spots or the recovery phase. Although there is still controversy as to which type of pedaling technique is more metabolically efficient (1, 8), the round pedaling reduces the load on the most important muscles for propulsion in cycling, i.e. the knee extensors (3). In this way, the work necessary to maintain the intensity of the exercise is distributed among other leg muscles (3), which would translate into a greater potential to use the knee extensors in the crucial moments of the competition. Traditionally, fixed-gear training has been considered as one of the main methods to improve the round pedaling technique (5, 6). However, this type of gear does not force the rider to pull up on the pedal during the upstroke, so its effectiveness in improving round pedaling is questionable. Therefore, the aim of the present investigation was to evaluate the acute and chronic adaptations in the pedaling technique of a group of track and road cyclists while pedaling with both fixed gear and a freewheel.
Materials and Methods 22 cyclists (13 track and 9 road cyclists) participated in the study (height: 179.5 ± 5.8 cm and 182.3 ± 3.4 cm; weight: 75.7 ± 6.6 kg and 68.0 ± 4.0 kg; age: 21.7 ± 2.4 years and 21.7 ± 2.5 years, respectively) after giving informed consent. Track cyclists were used to train with both fixed gear and a freewheel, while road cyclists had never pedaled before with a fixed gear. A track bike was equipped with a system for measuring the tangential and radial forces relative to the crank applied to both pedals (PowerForce, O-Tec, Germany). Two identical freewheel sprockets were used for the tests, one of which was modified to remain fixed. These sprockets were mounted on a double sprocket track wheel, so that variability due to the material used was minimized. With each of the two sprockets, subjects pedaled on a traditional Elite E-motion roller at three cadences (60, 80 and 100 rpm) and two different resistances (low and high) for one minute. Road cyclists were tested first with the freewheel, whilst track cyclists were tested in random order. Forces applied to both pedals were recorded at 1000 Hz and the last 20 seconds of each trial were used for subsequent analysis. To quantify pedaling technique, the following variables were measured: positive impulse (IMP+), negative impulse (IMP-), positive impulse proportion (PIP), index of effectiveness during the whole pedal stroke (IE360), downstroke (IE0-180) and upstroke (IE180-360).
Results Due to the overall symmetry existing between the force applied with both legs, only the data relative to the left leg are presented. The low resistance setup of the roller was weight dependent, and increased proportionally with the riders’ weight. There were no significant differences between the fixed gear and freewheel conditions in any condition or group. However, road cyclists showed smaller left leg power and IMP+ on the low resistance conditions. Table 1 shows the results at 80 rpm, as representative of the other cadences. Table 1. Means ± SD for the variables in Track and Road cyclists for the left leg. TRACK cyclists 80 rpm, low resistance 80 rpm, high resistance Fixed Gear Freewheel Fixed Gear Freewheel Left Power (W) * 86.7 ± 7.5 * 87.3 ± 7.6 165.9 ± 9 163.5 ± 10.9 IMP+ (N·s) * 56.6 ± 5.1 * 56.59 ± 5.2 89.72 ± 5.8 89.51 ± 5.9 IMP- (N·s) -11.7 ± 2.3 -11.92 ± 2.6 -4.27 ± 1.9 -4.85 ± 2 PIP (%) 82.9 82.6 95.5 94.9 IE360 0.45 ± 0 0.44 ± 0 0.65 ± 0 0.64 ± 0 IE0-180 0.76 ± 0 0.76 ± 0 0.78 ± 0 0.78 ± 0 IE180-360 -0.36 ± 0.1 -0.36 ± 0.1 0.03 ± 0.1 -0.02 ± 0.1 ROAD cyclists 80 rpm, low resistance 80 rpm, high resistance Fixed Gear Freewheel Fixed Gear Freewheel Left Power (W) 76.7 ± 5.6 76.9 ± 4.8 161.8 ± 6.1 159.4 ± 5.9 IMP+ (N·s) 51.13 ± 5.2 51.81 ± 4.1 87.84 ± 4.1 86.63 ± 3.1
DOI: 10.1080/02640410802526916 1519/jsc.0b013e3181b3e094 1080/02640414.2015.1127987 3389/fphys.2013.00232
Issue No: Vol. 11, No. 3
- EFRT: A realistic model of human exercise, fatigue and recovery
Authors: Axel Finke
Abstract: We discuss mathematical models for endurance exercise. Such models are needed to accurately assess athletes' fitness (e.g. for guiding training or identifying talent); and to predict performances (e.g. for optimising race strategies and pacing in track-cycling events). So-called W’-balance models, based around the “critical power” paradigm, are the current state-of-the-art. Unfortunately, W’-balance models cannot account for many essential qualitative features of endurance exercise. For instance, they fail to adequately capture that: (a) low (“heavy” or “moderate”) exercise intensities cannot be sustained indefinitely; (b) pacing impacts exercise tolerance; (c) exercise modality affects subsequent recovery; (d) fatigue from prolonged exercise changes the power–duration relationship (a.k.a. the “durability” concept). We introduce the exercise, fatigue and recovery tracking (EFRT) model – a novel and rigorous framework for endurance exercise; and demonstrate that the EFRT model is more realistic than W’-balance models in the sense that it can capture all the above-mentioned essential qualitative features of endurance exercise (and many more). The EFRT model is also highly parsimonious: it requires only a small number of parameters and all of these have meaningful interpretations: they represent speed, endurance, durability, and recovery.
Issue No: Vol. 11, No. 3
- MMP and Torque – duration profiles from u19 cyclists and WT
cyclists.
Authors: Yann BERTRON, Maximilien Bowen, Jean - Baptiste QUICLET, Pierre Samozino, Alexandre Abel, Alexandre Pacot, Frédérique Hintzy, Baptiste Morel
Abstract: Performance in cycling is often defines by the power produced by an athlete (i.e., power profile). Studies have tried to identify the differences between categories and levels. It has been showed that world tour cyclists have better qualities than the others. Moreover recently, it has been showed that power profile is mainly depend on the torque production capacities. The aim of our study was to investigate the torque at Mean Maximal Power – duration relationship by i) testing the fitting of the relative torque used in MMP from different durations ii) determine the differences between world tour cyclists (WT) and under nineteen cyclists (U19), because of the development strakes of this category. 17 u19 cyclists and 20 world tour participated in this study. Relative Power, cadence and relative torque data from one full season were used to determine the relative mean maximal power and relative mean torque relationships, for 10s, 1min, 2Min, 5min, 10min, 20min and 30min, and critical power was determined with the 3-parameter cp model. The goodness of fit was excellent (r² = .98 [.91-1). Significant differences were found from 5min to 30min and cp were found between the groups for relative power and relative torque data. No differences were found for the cadence. Torque duration relationship can be modelled and use to track performance of cyclists. Differences between world tour cyclists and under nineteen cyclists are mainly due to differences in torque capacities.
Issue No: Vol. 11, No. 3
- Development of multi sensor data acquisition system for micro-mobility
research
Authors: Salvatore Cafiso, Giuseppina Pappalardo, Riccardo Caponetto, Oliver Giudice
Abstract: With the increasing concerns of greenhouse gases and pollution, policy makers are supporting cycling as commuter mode of transport in urban areas. Moreover, during Covid-19 period, cycling was further appreciated by citizens as an individual opportunity of mobility. Unfortunately, as bicycle use increases, at the same time the rate of bicycles involved in road crashes has increased, as well. Data coming from European statistics shows that the rate of fatal accidents for cyclists in urban roads has increased from 2010 to 2018 by +6% in contrast to the decrease of all the other modes of transport. Therefore, cyclists’ behavior, safety, and comfort is becoming more and more of interest for research. Compared to the other mode of transport that are moving to always higher levels of automation, the micro-mobility vehicles (e.g. bicycle, e-scooters) suffer of a "digital divide" in terms of availability of technologies and sensors on board, often limited only to the smartphone capabilities (i.e low frequency GPS, camera, accelerometers). That limits the opportunities for high dimension and quality data collection and analysis. This paper present a multi sensor data acquisition system designed to be installed on a bicycle. Within the "Safedemon" project, a hardware architecture and processing system were developed which acts as a data logger for different types of sensors with a synchronization system based on UTM time. The system is modular and allows to acquire and synchronize high-frequency data from different sets of sensors: A) Sensors of physical data related to driving dynamics (GNSS/IMU) The first group consists of a GNSS/INS solution that integrates a multiband RTK/GNSS receiver, which can monitor the global GNSS constellations (GPS, GLONASS, GALILEO, Beidou, QZSS) with the ability to track up to 80 channels. To support the receiver, and to improve the accuracy of position fix during GNSS interruptions, there is a 6-axis inertial sensor array (3-axis accelerometer and 3-axis gyroscope). The whole system can ensure, through the integration of Real-Time Kinematic (RTK) and Precise Point Positioning (PPP) algorithms , sub-meter level accuracy at a measurement frequency of up to 100Hz even in the shortage or prolonged absence of any GNSS signal. Moreover, 3 axial accelerations and rotations can be recorded till to the higher frequency of 200 Hz. B) Sensors related to driver behavior and workload (eye tracker, EEG, HR) The second group consists of 3 wearable devices: 1) an earphone which, by means of a biometric sensor, allows continuous measurement of heart rate, oxygen saturation and blood pressure; 2) a headset that allows to measure the electrical activity of the brain (EEG) in the EEG power spectra (Alpha waves, Beta waves); 3) an eye tracker consisting of glasses with an integrated video camera system designed to frame what is in front of the wearer of the glasses. The orientation of the pupils is then calculated on this image in order to effectively estimate where the user is looking (gaze). To avoid clutter and interference with user comfort, all wearable device data is transmitted as a serial stream of bytes over Bluetooth via a standard Bluetooth Serial Port Profile (SPP). C) Sensors for analyzing the road context (camera, radar) The third group of sensors is devoted to detect the road environment and traffic conditions around the probe vehicle. It is composed by two cameras with an overall Field of View of 180 degrees and a 79 GHz short range radar to detect and track range, velocity, and angle of any moving object in the field of view of the sensor. The system has been evaluated and tested to ensure the accuracy and reliability of the collected data. As a result, the proposed system allows highway researchers to select among a wide range of measures to analyze the behavior, safety, and comfort of the cyclists riding In any road and traffic context. Additionally, the system can be easily installed to other micro mobility vehicles like e-scooter.
Issue No: Vol. 11, No. 3
- Optimizing performance in cycling through machine learning
Authors: Tim Verdonck, Steven Latré, Jan Boone
Abstract: In professional sports, optimal performance requires a balance between training and subsequent recovery. To follow-up on this balance, it is important to monitor training load, symptoms of fatigue and predict changes in performance. At present, performance is mostly monitored and predicted based on white-box mathematical models, which were historically based on rigorously configured test protocols and taken under controlled settings with a moderate number of athletes. While these models have clear scientific evidence and provide great value, they are often too coarse grained to assess and predict subtle changes in performance. Moreover, in monitoring performance through e.g., lactate tests, the disruption of the athlete’s training schedule can also not be neglected. On the other hand, a lot of individual data is available from wearable sensors during training and in everyday life: physiological metrics such as heart rate and heart rate variability, performance metrics such as power and contextual metrics such as altitude. Recent advances in machine learning allow building a more personalized model for an individual athlete: the plethora of data that is available allows building a much more fine-grained and individualized model for monitoring and predicting performance. However, machine learning is facing its own challenges: it is essentially a black-box model and the data that is used is often noisy, as it is collected under non-controlled circumstances. In this talk, we will explain how we will balance such white-box and black-box approaches. We present advanced machine learning models for approximating the performance measures based on this huge amount of individual data. More specifically, we will present specific machine learning modules for advanced performance monitoring such as estimating individualized fitness-fatigue levels, LT1/2 threshold prediction and automatic training anomaly detection.
Issue No: Vol. 11, No. 3
- A Novel Submaximal Field Test of Fatigue Resistance in Professional
Cyclists
Authors: Borja Martinez-Gonzalez, Andrea Giorgi, Samuele M Marcora
Abstract: Induced by a given amount of prior accumulated work, it should be possible to quantify fatigue resistance by measuring changes in perception of effort, not requiring a maximal effort from the athletes. The aim of the study was to investigate the impact of prior accumulated work on perception of effort during submaximal exercise in professional cyclists. Seven male professional cyclists performed a submaximal field test consisting of three 5-minute bouts at three different power outputs in both fresh and fatigued states. Heart rate (HR), ratings of perceived exertion (RPE), and power output (PO) data were collected. Before the submaximal test in the fatigued state total work done was 3244 ± 83 kJ. RPE and HR were higher in the fatigued state than in the fresh state (p < 0.05). Absolute and relative PO during the submaximal test were not different between fresh and fatigued states (p > 0.05). The main findings of the study are that both RPE and HR during submaximal exercise are sensitive indicators of the state of fatigue induced by more than 3000 kJ of work done in professional cyclists. Therefore, we proposed a feasible submaximal exercise protocol to test fatigue resistance in the field.
Issue No: Vol. 11, No. 3
- Estimation of Anaerobic Threshold with dynamic transfer function models
based on heart rate and power in cycling
Authors: Loes Stessens
Abstract: The anaerobic threshold is an important marker commonly used in cycling to identify training zones and monitor training progress. However, monitoring of the anaerobic threshold is not performed on a regular basis due to the high costs, invasive blood sampling and time-intensive test protocols. Mathematical modelling might form a suitable alternative for regular monitoring of performance. Furthermore, modelling allows for identifying the effect of certain influential variables on the performance, resulting in performance prediction. They might enable more practical applications, especially in combination with wearable technology. In cycling, the heart rate, power and cadence are already continuously measured and monitored during training and competition, making them particularly suitable for integration in a modelling technique. This study attempts to estimate the anaerobic threshold with linear time-invariant and linear time-varying models based on the heart rate, power.
Issue No: Vol. 11, No. 3
- To shuffle or not to shuffle
Authors: Callum Barnes
Abstract: can be found within the attached document.
Issue No: Vol. 11, No. 3
- Gender related differences in pressure distribution, pelvis movement and
subjective perception during cycling
Authors: Sophie Richter, Stefan Schwanitz, Frank I. Michel
Abstract: This research aims to examine and compare the saddle pressure distribution, pelvis movement and subjective feedback regarding perceived saddle pressure and stability of male and female cyclists. For this corresponding data are recorded after three minutes of sporty cycling. The findings Indicate notable differences, which can be attributed to anatomical variations between genders. These results have practical Implications for the design of saddles and seat pads, as they highlight the need for gender-specific considerations In cycling equipment.
Issue No: Vol. 11, No. 3
- Chain wear and elongation in Elite cycling: a case study
Authors: Remi Aubert, Frederic Grappe, Xavier Roizard, Tissot Vincent, Fabrice Lallemand
Abstract: In modern cycling, chain drives are commonly used since they are reliable and very efficient (1). However, their efficiency is known to be a function of chain wear, being highest after a few break-in kilometres and then slightly decreasing with the accumulated kilometres (2). Bicycle mechanics usually use mechanical gauges in order to check the chain elongation and therefore decide when to replace the chain. However, chain elongation can result from both material loss due to friction and mechanical elongation caused by a plastic deformation of the chain elements, which would be independent of material loss. Moreover, the wear of chain link elements is not uniform (3). The aim of this study is to determine the part of plastic deformation on chain elongation. The hypothesis is that plastic deformation is highly responsible for chain elongation. Identical chain spans were tested either on fatigue on a traction machine or in real riding conditions, on a same number of chain cycles (150 000). Since the traction machine acts only in the longitudinal axle, there is no friction occurring during these tests which therefore cause mechanical elongation but no wear. On the other hand, real riding conditions combine both traction and friction. Chain spans elongation was measured throughout the tests. For real riding conditions, parameters such as power output (W), pedalling cadence (rpm), gear ratio, weather and lubrication were controlled. They allowed to determine the chain tension Fn (N), the number of chain cycles and the mechanical work W endured by the chain roller (Nm).
Issue No: Vol. 11, No. 3
- Automated PTZ framing of track cyclists using timing loops
Authors: Maarten Slembrouck, Robbe Decorte, Jelle De Bock, Steven Verstockt
Abstract: Track cycling coaches are mostly busy focussing on what their athletes are doing live. Therefore, they often lack the time to capture videos of the performances of their athletes during practice or competition from which the athletes can learn a lot. We propose a system that can automatically capture track cyclists using a PTZ camera and timing loops while limiting the amount of work for the coaches and technical staff.
Issue No: Vol. 11, No. 3
- Low cost and personalized highlight generation during cycling races
Authors: Robbe Decorte, Jelle De Bock, Maarten Slembrouck, Steven Verstockt
Abstract: Our smart Sensor-driven Tripod focuses on supplying a unified sensor / video solution to capture personalized highlights for participants of cycling races. It does so by capturing video and sensor data simultaneously. The clipping mechanism is driven by sensing nearby signals of ANT+ capable devices. The hardware is accompanied by an online interface where participants can manage their sensors and discover for which events they can generate clips. The device has been deployed and tested in two amateur level cycling races in which it provided clips for all but one of the registered participants without interruptions.
Issue No: Vol. 11, No. 3
- Will wearable sweat lactate sensors be the next big thing in cycling'
Authors: Kevin Van Hoovels, Jan Boone, Maria Cuartero, Gaston A Crespo
Abstract: The use of wearable sensors in cycling is rising. Besides heart rate, we can now measure more and more variables in real-time like glucose (in interstitial fluid), core body temperature (at the heart rate belt), muscle oxygenation (with NIRS at the upper leg), and sweat rate (with wearable sensors). These sensors can give more insights into what is happening during exercise and can be used to optimize performance. However, the usefulness of some of these different measurements is still under debate. One of the recent additions to the list of variables that can be measured with wearable sensors is the concentration of lactate in sweat. Since blood lactate is a key performance indicator in sport physiology and can be used to monitor exercise intensity, there is a lot of interest in measuring lactate during exercise. Nonetheless, blood lactate has the disadvantages that it is invasive, painful, not continuous, and that the exercise has to be interrupted to measure. If lactate can be measure non-invasively and in real-time in sweat, this will open much more insights and possibilities to monitor lactate during exercise. However, the relationship between sweat lactate and blood lactate still remains unclear. Since sweat lactate concentrations are higher in sweat (1-30 mM) than in blood (1-15 mM), there is debate on the origin of lactate in sweat. Lactate can be produced by the sweat glands itself, derivate from the lactate in blood, or a combination of both. Further research is needed to explore the origin of lactate in sweat. In the past researchers were using different sweat collection methods to analyze lactate in sweat. With these methods sweat was collected during a certain time period and the lactate concentration was analyzed afterwards. Most of these studies found no or even a negative relationship between sweat lactate concentration and exercise intensity. This can probably be explained by the dilution of the sample due to the increase in sweat rate with increasing intensity. With the recent developments in wearable sweat sensors, sweat lactate can now be measured continuously when there is a constant supply of new sweat. Using these sensors, there is no dilution of the samples which can results in a positive relationship between sweat lactate and exercise intensity (and also blood lactate). This article will give an overview of the existing literature about the link between sweat lactate and exercise, and the usability of wearable sweat lactate measurements in endurance sports like cycling.
Issue No: Vol. 11, No. 3
- Monitoring and Analysis the Power Profile I.R of Iran Elite Men National
Road Cycling Team pre in Asian Championship 2022
Authors: Alireza Iri
Abstract: Monitoring athletes has become an integral part of the overall preparation of athletes. Many athletes, coaches, and support staff are adopting an increasingly scientific approach to designing and monitoring training programs. The challenge for practitioners is to stop collecting data for no reason but to use all this information to help their athletes improve their performance. Systematic monitoring of physiological and psychological variables related to performance helps practitioners measure the effectiveness of their training programs and decide how to modify or update those programs. As mentioned, individuals need to understand the reasons for monitoring athletes and how to use the information to improve their performance. which will increase the effectiveness of any monitoring program from the side of athletes and practitioners. One of the most important variables in road cycling is functional threshold power (FTP), which is obtained by a 20-minute FTP test and the average power output of cyclists in relation to their weight (W/Kg). We conducted a 20-minute FTP test at the Iran Cycling Federation testing center before the 2022 Asian Championship in the national team camps of those invited to the camp in three stages out of twenty people. First, the cyclists were weighed before the test. And testing was done. And by reviewing the test results and power profiles of cyclists, the training and progress of cyclists were monitored. By checking the power profile or W/Kg of the cyclists in the last stage, we were able to introduce the best 7 people to the coach by considering the needs of the national team coach. The results obtained in the last stage of testing from 7 average cyclists' Power on weight was 4.36 and with an average weight of 69.01. Monitoring was done officially for the first time in the Iranian Cycling Federation. And with monitoring and analysis, we were able to monitor the people invited to the 3 stages of the camp and monitor their progress and finally choose the best people. Iran's men's national cycling team was able to win 3 medals in this competition. Monitoring and analysis of cyclists can be done in more time before the competition, and if we consider other factors, better results will definitely be obtained.
Issue No: Vol. 11, No. 3
- Power loss of the chain drive in tandem bicycles
Authors: Albert Smit, Stephan van der Zwaard, Ina Janssen, Thomas W.J. Janssen
Abstract: :
Introduction: Tandem cycling is a Paralympic sport, in which two cyclists ride on one tandem bicycle. The front rider (pilot), is responsible for the steering, braking, changing gears, and tactics. The back rider (stoker), has a visual impairment and is responsible for responding to changes in cadence and generating power. As the average difference in finish time between obtaining a medal and becoming 4th was 0.5% at the Tokyo 2020 Paralympics for tandem cycling track and road time trial events, much time and effort in the competitive preparation is focused on enhancing individual and team performance. One way to increase performance is by minimizing power losses of the chain drive, which consists of two chains in tandem cycling, the primary and secondary chain. This study aimed to determine the mechanical power loss due to the chain drive of a race tandem bicycle and whether power losses in the chain drive are different for the pilot and stoker. Also, the effect of chain wheel size on power loss was studied. Methods: The tests were performed on a tandem bicycle to assess power losses in the chain drive by applying a fixed power input to of the cranks with an electric motor and measuring the power output at the location of the rear wheel. This was done at the rear crank without the secondary chain to simulate a solo bicycle, and with the primary and secondary chain attached to the rear crank to simulate power input only by the stoker on a tandem. The power input was also delivered to the front crank using both primary and secondary chains to simulate power input only by the pilot. In each situation, gears 53-11 and 53-13 were used. Results: Power losses in the chain drive were significantly affected by bicycle type and the position of the tandem cyclist (p<0.001). Results showed that the power loss in the solo bicycle (mean power loss = 1.9% ±1.5%) was significantly less than at the tandem stoker (3.7% ±2.4%, p<0.001) and pilot (3.0% ±1.8%, p<0.001), with a significant difference between pilot and stoker (p<0.001). However, these differences between pilot and stoker were only present at a power output below ~250W. Results also showed that in tandem bicycles a gear ratio of 53-11 (mean power loss = 4.0% ±2.8%) resulted in a higher power loss than 53-13 (2.9% ±1.7%; p<0.001). Conclusion: Power loss due the chain drive in tandem cycling is higher than in solo cycling. It is affected by the chain wheel size, with a larger chain wheel resulting in a lower power loss. It is also affected by the location of the power input, with the location of the pilot resulting in a lower power loss than that of the stoker, although only for the lower power zones. Keywords: transmission efficiency, para-cycling, power output
Issue No: Vol. 11, No. 3
- Effects of acute hypoxia at rest exposure on time trial performance of
national category cyclists.
Authors: Jesus
Abstract: The aim of this study was to analyze the effects of rest exposure to hypoxia at performance on a simulated cycling time trial (TT) in normoxia cycling. Nine cyclists of national class participated in the study. A single blind, cross-over randomised study in which participants performed two test sessions on two different days in the laboratory was conducted. First, they were exposed to normobaric hypoxia simulating an altitude of 4500 m above sea level (FiO2=0.09) or normoxia for 30 min. After hypoxia or normoxia exposure, participants performed a 20-min simulated TT. Mechanical performance variables, perceived exertion and economy and gross efficiency (GE) amongs other physiological variables were measured. The results showed that hypoxia exposure did not provoke any changes neither in physiological variables, mechanical performance variables and perception of effort (p > 0.05, ES = -0.03 – -0.25, trivial to small), nor in economy and GE (p > 0.05, ES = 0.450, small, -0.139, trivial, respectively). The results suggest that a 30-min rest hypoxia exposure does not affect performance in a 20-min simulated TT in a cycle ergometer under normoxic conditions. t
Issue No: Vol. 11, No. 3
- Optimizing the high-intensity interval session through workload
alterations in well-trained female and male cyclists
Authors: Tomas Urianstad, Ingvill Odden, Håvard Crantz Lorentzen, Ingvill Odden, Knut Sindre Mølmen, Håvard Hamarsland, Daniel Hammarstrom, Bent R. Rønnestad
Abstract: High-intensity interval training (HIT) sessions with a variable workload during the work periods has been considered more effective compared to HIT sessions performed at a constant workload; the optimal HIT design is unknown. This study investigated the isolated effect of power output distribution during three specific HIT sessions, not influenced by factors such as different training duration and different mean power output. 19 well-trained female and male cyclists (age, 22.6 (4.1); maximal oxygen consumption (VO2max), 70.3 (11.0) mL∙min-1∙kg-1) performed three different 6x8-minutes HIT sessions at a mean power output corresponding to the individual participants´ 40-minute maximal power output (FTP) on three consecutive days, in a randomized order: Session 1) 8-minute work periods with 30-seconds work periods at 118% of FTP separated by 15-seconds recovery periods at 60% of FTP (30/15), Session 2) 8-minute work periods performed at a steady power output corresponding to 100% of FTP (CON), Session 3) 8-minute work periods performed as two continuously changing 60-seconds work periods at 110 and 90% of FTP, respectively (60/60). During the HIT sessions, both mean oxygen consumption (%VO2maxHIT) and time ≥90% of VO2max were higher in 30/15 compared to 60/60 (p=0.045 and p=0.042, respectively) and CON (p=0.001 and p=0.001, respectively). In conclusion, 30/15 led to a higher %VO2maxHIT and more accumulated time ≥90% of V̇O2max than both 60/60 and CON, suggesting that this HIT protocol provides the most effective training stimulus.
Issue No: Vol. 11, No. 3
- The higher fraction of V̇O2max during interval training, the greater
gains in performance
Authors: Ingvill Odden, Lars Nymoen, Tomas Urianstad, Daniel Hammarström, Knut Sindre Mølmen, Bent R. Rønnestad
Abstract: The fraction of maximal oxygen consumption (VO2max) achieved during a high-intensity interval training (HIT) session and the time it is sustained ≥ 90% of VO2max have been suggested as good criterions for judging the effectiveness of the HIT session. However, scientific findings supporting this assumption are surprisingly still unavailable. To our knowledge, the present study is the first who continuously has measured participants oxygen consumption (VO2) during every HIT session throughout an entire exercise training intervention. Our finding that higher fractions of VO2max elicited during HIT sessions translates into greater endurance performance improvements covers a great gap in the existing literature of applied exercise physiology.
Issue No: Vol. 11, No. 3
- Cycling performance after accumulated load: does durability change during
a cycling season'
Authors: Jens Voet, Robert Lamberts, Jos de Koning, Teun van Erp
Abstract: Introduction:
Durability is the ability to produce high power outputs after accumulated load (at the end of a race), which has been shown to be an important success factor in professional road cycling (van Erp et al. 2020; Leo et al. 2021; Mateo-March et al. 2022; Muriel et al. 2022). Gross efficiency (GE), fat oxidation (FATox) and carbohydrate oxidation (CHOox) have been proposed as underlying physiological factors for durability, as changes have been shown to be related to a decrease in performance after accumulated load (Noordhof et al. 2020; Passfield & Doust, 2000; Stevenson et al. 2022), although there is much debate on this topic. Therefore, the aim of this study is to investigate durability and the underlying physiological factors in semi-professional cyclists. Secondly, this study investigates how durability and certain physiological factors changed during a cycling season. Materials and methods:
In total, 16 semi-professional cyclists (10min PO: 379±22 W) visited the lab on 3 occasions: Start of pre-season (PRE), start of race season (START), and halfway into the race season (IN). Testing days included: a warm-up at 55% of VO2peak power at which GE, FATox and CHOox were determined, followed by a 1min and 10min time trial to measure power output (TT1minfresh, TT10minfresh). After 3hours of endurance training (31±5 KJ/kg) the same protocol was repeated to investigate the influence of accumulated load on performance (TT1minfatigued and TT10minfatigued) and physiological parameters (GE, FATox and CHOox). Differences between PRE vs START vs IN and fresh vs fatigued were investigated using a mixed-effects multilevel model. When significant (p<0.05) main effects occurred, Bonferroni post-hoc was executed for pairwise comparisons. Results:
No differences were found between TT1minfresh at PRE, START and IN and TT1minfatigued at PRE, START and IN, however TT1minfresh was significantly higher than TT1minfatigued at PRE, START and IN (figure 1). TT10minfresh did not differ from TT10minfatigued on all occasions, however, both TT10minfresh and TT10minfatigued were lower at PRE compared to START and IN (figure 1). CHOox (PRE and START) and GE (START) were lower in fatigued compared to fresh state, while FATox was higher in fatigued compared to fresh (PRE and START). In addition, GEfresh was higher at START and IN compared to PRE, while there was a decrease in FAToxfatigued from PRE and START to IN. Lastly, an increase was noted from PRE to START in CHOoxfatigued and PRE to IN in GEfatigued and CHOoxfatigued. Discussion:
This study is to the best of the authors knowledge, the first to present the changes in power output, gross efficiency and substrate oxidation before and after accumulated load during a full cycling season. Performance over short efforts (TT1min) is affected by fatigue but doesn’t improve from PRE to IN. Performance over longer efforts (TT10 min) is not significantly affected by accumulated load, however, improves throughout the season (from PRE to IN). As the total load at the beginning of the fatigued test was ± 40 KJ/kg, it could be suggested that the protocol in the current study was not fatiguing enough, with decline in performance in professional cyclists found after 50 KJ/kg (van Erp et al. 2020). However, other studies already found an earlier decline in performance (Leo et al. 2021; Mateo-March et al. 2022; Muriel et al. 2022). Also, previous studies are based on race data. As not only the accumulated load, but also the intensity of that load plays a role in an impaired performance after exercise (Vermeire et al. 2023), it could be suggested that the intensity of the races was higher as compared to the controlled environment in the current study. Not only the load, but also intensity plays a role in an impaired performance after exercise Gross efficiency was not affected by the accumulated load in the current study, which is in contrast with previous research (Noordhof et al. 2020; Passfield & Doust, 2000) . As the level of the cyclist in the current study is higher as compared to previous research, it could be argued that the protocol was not fatiguing enough to result in a decreased efficiency. However, GE seems to improve throughout the season (from PRE to IN). Substrate oxidation changes after accumulated load with FATox increasing and CHOox decreasing, as in line with previous research (Stevenson et al. 2022). However, this difference diminishes from PRE to IN, because of higher CHOox and lower FATox after accumulated load. It could be suggested that this shows a better durability during the season compared to the pre-season and that the ability to maintain CHOox high in fatigued state results in better performance (although not significant).
Issue No: Vol. 11, No. 3
- The effect of symmetry monitoring system on lower limb muscle activation
asymmetry in bike field test
Authors: Chia-Hsiang CHEN
Abstract: Purpose: The aim of this study was to access the effect of lower limb asymmetry in field test when symmetry measurement system intervenes. Methods: This study recruited 14 participants (height: 172.1 3.9 cm, weight: 64.2 5.3kg, age: 21.9 1.6 year-old). The wireless EMG was applied to observe the bilateral muscle activation in lower limb (rectus femoris, bicep femoris, tibialis anterior, gastrocnemius) with and without symmetry monitoring system in outdoor cycling. The asymmetry index (AI) was calculated by the percentage difference between right (R) and left (L) sides. The repeated measurement ANOVA was used. The significance level was set as =.05. Results: The intervention of symmetry monitoring system would improve the bilateral symmetry of rectus femoris and gastrocnemius. Conclusion: The intervention of symmetry monitoring system could improve the asymmetry phenomenon in lower limb, possibly postpone the onset of fatigue and reducer injury rate.
Issue No: Vol. 11, No. 3
- Anterior saddle conflict in women cycling : a case study
Authors: Lucas Leblond
Abstract: Women's cycling is growing rapidly, but as it is a recent development, women do not always find products that are suitable for them. It is well known that women are particularly sensitive about their seating position on the bike and have difficulties in finding the right saddle. The choice of saddle is often made by default. We have noticed that an unsuitable saddle can cause the pelvis tilt, as if to avoid resting on an irritating spine. The aim of our case study was to investigate the effects of a custom-made saddle against an anterior saddle conflict that had been going on for several years. Our subject is an international female cyclist who rides for a UCI Women Continental team. She had unilateral vulvar lymphoedema and knee pain on the same side. She was already wearing orthopaedic corrections to stabilise her position on the bike. The stability gain was partial. Knee and seat pain remained. We compared the athlete's original saddle with the custom-made saddle without foam and with foam. Kinematics, kinetics, saddle pressure and comfort perception were measured while riding at 70-75% of estimated MAP and with 2 different cadences: 90-95rpm (power) and 70-75rpm (strength). The bearing surface of the saddle increased significantly. The maximum saddle pressures were reduced. The distribution of lateral and anteroposterior pressures was clearly rebalanced. The saddle was perceived to be clearly comfortable. However, no changes could be detected in the kinematics and kinetics of pedalling. This case study seems to verify that material-specific saddle conflict is a reality. The custom-made saddle could be a solution to this indication. The advantages and disadvantages of the different customised techniques are however still to be studied, as well as the effect they could have on a larger group.
Issue No: Vol. 11, No. 3
- Performances of bicycle tyres - effect of vertical load and inflation
pressure
Authors: Gabriele Dell'Orto, Gianpiero Mastinu
Abstract: Tyre characteristics can strongly affect bicycle dynamics, therefore the overall bicycle performances. We already know the importance of longitudinal tyre characteristics (commonly known as rolling resistance), but the lateral characteristics are mostly ignored. Proper testing machines for bicycle tyres are required to measure the lateral characteristics, in order to have a full tyre characterization. The paper presents the results from an experimental campaign on road racing bicycle tyre. Vertical load may affect a lot the tyre parameters, as well as inflation pressure. Specifically, a variation in vertical load of 50 N may results also in 10% increase in cornering stiffness, the main parameter used to assess tyre lateral characteristics.
Issue No: Vol. 11, No. 3
- Creatine supplementation during a training camp in young professional
cyclists: a randomized controlled trial
Authors: Carlos Revuelta
Abstract: : Background: Growing evidence suggests that creatine supplementation can provide beneficial effects on exercise performance and recovery, particularly in strength/power sports. However, its effects on endurance athletes remain unclear. We aimed to assess the effects of short term creatine supplementation in professional cyclists during a training camp. Methods: Twenty-three professional U23 cyclist (19±1 years, peak oxygen uptake: 73.0 ± 4.6 ml/kg/min) participated in a six-day training camp. Participants were randomized to consume after each training session either a recovery drink along with a creatine supplement (20 g) (n = 11) or just the recovery drink (n = 12). Indicators of fatigue/recovery (Hooper index, Recovery-Stress Questionnaire for Athletes (RESTQ), countermovement jump), body composition, and performance (1-, 6-, and 12-minute time trials, as well as the estimated critical power) were assessed as study outcomes. Results: The training camp resulted in a significant (p<0.001) increase of training loads (e.g., +50% increase in training time and +61% Increase In training stress score compared with the preceding month), which induced an increase in fatigue indicators (e.g., time effect for delayed-onset muscle soreness, fatigue, and total Hooper index, p<0.001) and a decrease in performance (e.g., time effect for critical power, p=0.020). A significant group by time effect (p<0.05) was observed for different recovery items (i.e., success, social recovery, and physical recovery) of the RESTQ, but no additional between-group differences were found for any of the analyzed outcomes. Conclusion: Short-term creatine supplementation seems to exert no consistent beneficial effects strenuous training period in professional cyclists.
Issue No: Vol. 11, No. 3
- A Review of the effects of seat height and seat tube angle on cycling
performance and the implications for downward seat inclination
Authors: Andrew N Anderson, Babak Bazrgari, Katherine L Thompson, Fan Gao, Jody L Clasey, Michael A Samaan
Abstract: Due to the vast number of performance variables during road and off-road cycling, cyclists perform bicycle modifications to increase efficiency and to improve performance during cycling. In the past, these modifications sought to optimize the length-tension relationship in the lower extremity musculature and included alterations in seat height and seat tube angle as well as modifications which reduce drag and improve aerodynamics of the cyclist and the bicycle. More modern adaptation involves altering the angle of the saddle, most often to adopt a “downward tilt”. This adaptation arose from studies inspecting the effect of downward saddle tilt on comfort and prevention of pathologies leading to chronic pain but may have an impact on performance. The purpose of this literature review was to summarize prior work describing the effects of saddle height, seat tube angle and, primarily, saddle angle related to performance and efficiency of cycling. A seat height which approximates 100% of the trochanter height and 109% of inseam height is considered optimal for performance, while steeper (more inclined) seat tube angles provide improved comfort and efficiency when compared to less steep seat angles on flat and hilly terrain. Downward tilt of the saddle was shown to increase performance and comfort, but most of these studies were conducted while assessing uphill cycling, which is commonly performed by recreational cyclists. Changing the bicycle saddle angle to have a downward inclination was shown to increase performance during uphill bouts of cycling. Downward inclination of the saddle has potential to increase or at least maintain performance during flat bouts of cycling, but future investigation is needed to further substantiate this relationship.
Issue No: Vol. 11, No. 3
- Where are the world`s fastest Ironman® 70.3 race courses for
professional athletes'
Authors: Mabliny Thuany, David Valero, Elias Villiger, Marilia Andrade, Katja Weiss, Pantelis Nikolaidis, Ivan Cuk, Beat Knechtle
Abstract: The dominance of certain nations in certain sports disciplines is well knowed in scientific context. For triathlon, it has been reported that most of the finishers, and the fastest in Ironman® Hawaii originated from the United States of America. However, nothing is known regarding the role of specific race courses in athletes' performance. The present study aimed to analyze where the fastest split and overall race times for Ironman® 70.3 races were achieved. The locations of the fastest Ironman® 70.3 competitions were processed throughout 163 different event locations. Race records were aggregated by location, and the split and full finish times. The Ironman® 70.3 races in Dubai, Kronborg, and Mandurah presented the fastest race course. For split disciplines, the fastest swim times were recorded for women and men in the Ironman® 70.3 races in Busan, Panama, and Augusta. For cycling, the fastest times were achieved for both women and men in Ironman® 70.3 Tallinn, followed by the Ironman® 70.3 Dubai and Bahrain. The fastest running times were recorded for women and men in Ironman® 70.3 Kronborg, the Ironman® 70.3 Nice, and Les Sables d’Olonne. Differences among the race course were found, except for the running discipline. Professional triathletes and coaches could use this information to design optimal race courses and training strategies for performance improvement.
Issue No: Vol. 11, No. 2
- Effect of Seat Shear Forces and Pressure on Perceived Sitting Comfort in
Cycling
Authors: Victor Scholler
Abstract: Feeling comfortable on the bicycle is essential for professional cyclists to decrease pain and prevent pathologies. The pressure analysis appears to be a relevant tool to monitor how the changes in position and saddle characteristics affect the stress on genital tissues to prevent pathologies. Moreover, in everyday life sitting situations, other biomechanical sitting parameters such as shear forces influence the sitting comfort. Therefore, this study aimed to identify how the seat pressure and shear forces affect the perceived sitting comfort of twelve competitive road cyclists during a 20 min treadmill cycling exercise. Treadmill exercises were performed before and after a fitting optimization session that aimed to improve the perceived sitting comfort. The major result is that the fitting optimization session significantly improved the perceived sitting comfort by 77%. Such improvement was associated with the decrease in shear forces (-21±42%) applied by the cyclist on the saddle in the lateral-medial direction and the increase in peak pressure at sit bone left (+19±25%) and right (+28±63%) following the fitting optimization session. It would be induced by better stability of the cyclist’s pelvic on the saddle, therefore reducing the proportion of the shear forces applied on the saddle.
Issue No: Vol. 11, No. 2
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