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Abstract: Abstract The present study investigates the association between subjective wellness symptoms, and categorical point-of-care (POC) blood biomarkers of the free oxygen radical test (FORT), and systemic inflammation through high sensitivity C-reactive protein (Hs-CRP), in English Premier League footballers. Data from 38 male professional elite athletes (Mean Age = 25.8, SD = 4.4) from the English Premier League were included in the study, with a total of 674 individual testing records collected over an entire Premier League season. A player wellness questionnaire, along with fasted and rested point-of-care blood biomarker testing were collected weekly across the season. The wellness questionnaire collected subjective symptoms of illness and fatigue, while FORT and Hs-CRP were assessed through point-of-care analysis to highlight periods of excessive hydroperoxide production and systemic inflammation. Using a chi square goodness of fit model, results showed that there was a significant association between the frequency of symptoms logged and categorical POC blood biomarker data of FORT and HsCRP (P < 0.01). Of the records demonstrating normal levels of Hs-CRP and FORT concentrations, 27% logged symptoms with an average of 1.5 symptoms reported per answered record. Comparatively, excessive biomarker values demonstrated 55% of records having symptoms logged, averaging 2.4 symptoms reported per record. PubDate: 2022-11-29
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Abstract: Purpose To assess the effect of a 12 week resistance or aerobic training intervention on markers of cardio-metabolic function and sleep among male rotational shift workers. Method Thirty-eight sedentary, apparently healthy, male rotational shift workers were recruited and randomly allocated to a non-exercise control (CON) group, 3 sessions/week of moderate intensity continuous (MICT), or resistance training (RT) for 12 weeks in a semi-supervised setting. Pre- and post-testing assessed markers of cardio-metabolic function including peak oxygen uptake (VO2peak), glucose metabolism, insulin sensitivity, body composition, inflammatory markers, and 14 day actigraphy sleep assessment. Results Mean session attendance across the intervention was 25 (± 7) of a possible 36 sessions. A significant group by time interaction was observed for MICT, with lower c-reactive protein (CRP) values observed post-training (P = 0.049). A significant effect for time was observed for both MICT (n = 9; P = 0.04) and RT (n = 10; P = 0.021), increasing total sleep time (TST) following a night shift post-intervention. Data redistribution regarding exercise adherence: < 24 (N-ADHERE) or ≥ 24 (ADHERE) resulted in significant pre-to-post reduction in body fat (P = 0.024) and fat mass percentage (P = 0.014) among ADHERE. No differences were observed for any intervention group on insulin sensitivity, glucose metabolism or oxygen uptake. Conclusion The results of the current study support exercise as a valid intervention to improve the cardio-metabolic health of rotational shift workers. Average sessional attendance suggests shift workers face barriers to exercise that may need to be addressed to improve health outcomes. PubDate: 2022-11-24
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Abstract: Purpose The purpose of this study was to monitor the Indian national rowing team’s training regime and the changes that occur in the rowers’ body composition, muscle cell damage, and training load markers during the phases of preparation for an international competition. Methods Ten male and 9 female elite rowers from the national team underwent anthropometric assessment and blood tests during 17 weeks of training, at the end of general preparation (W4), preparation (W10), and pre-competition (W17) phase. Body fat% and somatotype were determined by Siri’s equation and Heath-Carter manual, respectively. Assessments of blood biomarkers included measures of creatine phosphokinase (CPK), lactate dehydrogenase (LDH), urea, uric acid, testosterone, and cortisol concentration. Results Changes in variables were estimated by repeated-measures ANOVA. Body fat% (P < 0.001; male: d = − 2.03; female: d = − 2.89) and endomorph (P < 0.05; male: d = − 2.05; female: d = − 0.68) decreased significantly at pre-competition, whereas weight, mesomorph, and ectomorph remained unchanged throughout training. Urea (male: d = − 1.47; female: d = − 1.46) and uric acid (male: d = − 0.74; female: d = − 1.71) showed a significant decrease at pre-competition phase in both groups. CPK concentration significantly (P < 0.05) decreased at preparation (d = − 1.05) and increased during pre-competition (d = − 1.28) in male rowers. LDH showed significant increase (P < 0.01) at preparation (male: d = 1.17; female: d = 2.02) and pre-competition (male: d = 1.28; female: d = 2.09) than base preparation. Whereas, no significant changes were observed in cortisol, testosterone, or T/C ratio in subsequent measurements. Significant correlation (P < 0.05) was found between LDH and T/C ratio with rowing timing in male rowers. The 2000 m rowing timing also showed a significant improvement at W17 compared to W4 (male: d = − 1.25; female: d = − 0.94). Conclusion In conclusion, our results showed that rowers encounter more muscle damage and less protein catabolism during training season. Additionally, it is evidenced that rowing performance improved and biochemical markers—particularly enzymes—altered largely with altered training load rather than anabolic or catabolic hormone concentration in rowers. PubDate: 2022-11-22
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Abstract: Purpose This study compared the effects of offset loading (OSL) versus traditional loading (TDL) in the bench press exercise on pectoral muscle thickness and bench press strength over a 4-week mesocycle. Methods: Twenty male participants aged 18–45 years with at least 5 years of bench press experience and a bench press one-repetition maximum equal to or greater than their body mass were randomly assigned to OSL and TDL groups. Before and after the 4-week mesocycle, pectoral muscle thickness was assessed via ultrasonography and muscle strength was assessed by bench press one-repetition maximum. Effects were explored with two-way mixed ANOVA and non-clinical magnitude-based inferences. Results: No group-by-time interaction was detected for any variable (P > 0.05). When compared to small magnitudes, the pectoralis major muscle thickness changes were likely greater in OSL compared to TDL for the dominant (ES = 0.70; 87% likely greater) and nondominant pectoralis (ES = 0.77; 91% likely greater) as well as the sum of both pectorals (ES = 0.80; 92% likely greater). Similarly, a likely greater effect for absolute (ES = 0.57; 82% likely) and relative (ES = 0.67; 85% likely) bench press strength was seen with OSL. Conclusion: Magnitude-based inferences interpreted here support the notion that OSL may be an advantageous training modality to enhance pectoral muscle thickness and bench press strength. PubDate: 2022-11-16
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Abstract: Purpose This study investigated the optimal total sleep duration per day required by collegiate athletes to maintain the physical and mental health-related quality of life (HRQOL), compared with non-athlete students. Methods In this cross-sectional study, a questionnaire survey was conducted to assess demographic variables, lifestyle and sleep habits, and HRQOL in 392 collegiate students (non-athletes, n = 174; athletes, n = 218). Physical component summary (PCS) and mental component summary (MCS) were assessed using the short-form-8 health survey. Participants with both good PCS and MCS were defined as having a good HRQOL. To confirm an association between the total sleep duration per day and good HRQOL, logistic regression analyses were conducted in non-athlete students and collegiate athletes separately. Subsequently, receiver-operating curve (ROC) analyses were performed for the detection of the cut-off point of total sleep duration per day sufficient to maintain a good HRQOL. Results The average total sleep duration per day was 7 h 19 min for collegiate athletes, and 78.9% of them had a worse PCS. The cut-off point of total sleep duration per day to maintain good HRQOL for collegiate athletes was 7.92 h (area under ROC, 0.64; P = 0.038; sensitivity, 75.4%; specificity, 57.9%), which was longer than 6.79 h for non-athlete students. Conclusion Collegiate athletes required longer nocturnal sleep than non-athlete students. Nevertheless, their habitual nocturnal sleep duration was shorter compared to their optimal duration; around 70% of them faced chronic insufficient sleep. Improving sleep habits and sleep education is important in maintaining their good health-related quality of life. PubDate: 2022-11-15
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Abstract: Purpose Insoles with various wedges have effects on the biomechanical aspects of human movement. The aim of the present study was to investigate the immediate effects of 9 insoles while running on the myoelectric activity of selected trunk muscles. The conditions were no wedge, posterior, anterior, medial, lateral, posterior-medial, posterior-lateral, anterior-medial, and anterior-lateral. Muscles included were rectus abdominis, external oblique, internal oblique, latissimus dorsi, thoracic erector spinae, lumbar erector spinae, multifidus, and quadratus lumborum during running. Methods Twenty-five (n = 25) able-bodied males participated in this quasi-experimental study. Repeated measures analysis of variance test was used to compare dependent variables among various insole wedges. Results Significant differences (P = 0.001) in normalized mean amplitude index between the following wedge conditions were measured while running: posterior-lateral/medial (5.67 ± 1.01 vs. 4.73 ± 1.09) and posterior-lateral/anterior-medial (5.67 ± 1.01 vs. 4.52 ± 1.20) for the internal oblique muscle along with posterior-lateral/anterior (11.44 ± 2.42 vs. 9.26 ± 2.35) for the lumbar erector spinae muscle. Similarly, normalized peak amplitude index differences in the medial/anterior-lateral (9.79 ± 3.33 21 vs.12.03 ± 3.16) and lateral/anterior-medial (11.6 ± 2.56 vs. 9.25 ± 2.38) for the internal oblique muscle and posterior-lateral/anterior-medial (9.58 ± 2.26 vs. 8.78 ± 2.15) for the quadratus lumborum muscle were measured. In contrast, no significant difference was observed for the median frequency index among various insole wedges during running (P > 0.0014). Conclusion Decreased activity in the medial wedged conditions may have important negative consequences for the spine, pelvis, and dynamic core. These results provide insights into the effect of various orthotic designs on the EMG activity of central core muscles. Higher activation in an anterior-lateral wedge and lower activation in a medial wedge for core muscles can have clinical relevance, where there is a need to increase, or avoid decrease, core muscle activity. PubDate: 2022-11-15
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Abstract: Purpose The purpose of this study was to examine the responses of electromyographic (EMG) and mechanomyographic (MMG) amplitude across the torque spectrum in pre- and post-pubescent males and females. Methods Forty pre-pubescent (mean ± 95% confidence interval, age = 9.79 ± 0.35 years, n = 10 males, n = 10 females) and post-pubescent (age = 17.23 ± 0.58 years, n = 10 males, n = 10 females) participants completed this study. Participants completed maximal voluntary isometric contractions (MVICs) of the forearm flexors and extensors, as well as isometric ramp muscle actions. EMG and MMG amplitude were quantified from the biceps brachii, brachialis, and brachioradialis during all muscle actions. EMG and MMG amplitude during the isometric ramp muscle actions were normalized to EMG and MMG amplitude from the MVICs. Results The pre-pubertal group tended to have greater relative EMG amplitude across intensity (P < 0.050), while the post-pubertal group had a more pronounced increase in EMG amplitude at higher intensities. Similarly, the pre-pubertal group tended to have greater relative MMG amplitude across intensity (P ≤ 0.004) that plateaued earlier than the post-pubertal group (55% vs. 65%–75% of MVIC). Additionally, the pre-pubertal group had greater coactivation across intensity (P ≤ 0.001). Conclusion The greater relative EMG and MMG amplitude in the pre-pubertal group, in conjunction with the earlier plateau in MMG amplitude for the pre-pubertal group and greater coactivation, suggests less efficient muscle activation and motor unit recruitment strategies during pre-pubescence. Taken together, the findings of the present study suggest that growth-mediated changes in neuromuscular function lead to improvements in the efficiency of muscular activation and augmentations in motor unit recruitment strategies. PubDate: 2022-11-15
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Abstract: Abstract Live high train high (LHTH) is the original method of altitude training used by elite athletes to enhance sea-level performance. Whilst many anecdotal reports featuring world-class performances of elite athletes at sea-level following LHTH exist, well-controlled studies of elite athletes using altitude training under ecologically valid conditions with training well characterised are still lacking. The literature is equivocal when considering the ergogenic potential of LHTH, and given the majority of controlled studies do not report enhanced sea-level performance, some scepticism regarding the efficacy of LHTH persists. Despite this, LHTH remains a popular form of altitude training utilised by elite athletes, with numerous case studies of champion athletes employing LHTH solidifying the rationale for its use during preparation for competition. Discussion of factors affecting the response to LHTH are often related to compromising either the hypoxia induced acceleration of erythropoiesis and production of red blood cells, or the maintenance of oxygen flux and training intensity at altitude. Regarding the former, iron status and supplementation, as well as hypoxic dose are often mentioned. Concerning the latter, reduced oxygen availability at altitude leading to athletes training at lower absolute intensities and the relative intensity of training sessions being clamped as equivalent to sea-level, thus also reducing absolute training intensity are frequently discussed. Other factors including immune function and the timing of competition following LHTH may also contribute to an observed performance. Less considered in the literature are those factors specific to elite athletes, namely the repeated use of altitude camps throughout a season, and the influence this may have on subsequent performance. The current narrative review aimed to summarise the current literature pertaining to LHTH in elite athletes, and furthermore describe several factors affecting performance following altitude training. PubDate: 2022-11-04
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Abstract: Purpose Special tactical units differ from other police departments, for having more physically demanding tasks and occupations. Therefore, the aim was to analyze: (i) the differences in anthropometrics, body composition, and physical performance variables between those officers with the highest and lowest lean mass (LM) and fat mass (FM); and (ii) the associations between body composition (i.e., FM and LM) and some selected performance variables. Methods Thirty-six special operations officers (n = 36, age: 35.97 ± 5.50 years) volunteered to participate in this study. Participants were assessed for anthropometrics and body composition through skin-fold measures. Additionally, fitness was evaluated using appropriate physical tests (i.e. 30-m sprints, vertical jump, strength and endurance). Afterwards, participants were divided according to their level of LM and FM into: high (LMhigh and FMhigh) and low (LMlow and FMlow). Results Regarding strength and jump performance, LMhigh and FMlow obtained better estimated values in Squat (1 repetition maximum [SQ1RM]), and jump height (P < 0.05; ES = 0.62–1.29), although non-significant but small differences were observed for relative strength (P = 0.107; ES = 0.54). In terms of sprint and endurance, the results indicated that LMhigh and FMlow obtained significantly better performances across all measures (P < 0.05; ES > 0.89), except for endurance between FMhigh and FMlow (ES = 0.25–0.65). In addition, FM and LM were significantly associated with physical performance (P < 0.05; r > 0.383) in most of the variables of this study. Conclusion Higher LM and lower FM are determinant factors of physical performance in this population. Moreover, FM and LM seemed to be detrimental for physical performance as shown by the moderate to large correlations observed. PubDate: 2022-11-02
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Abstract: Introduction Countermovement vertical jump testing has become a staple in athlete assessment protocols. As the popularity of jump testing has grown, a need and interest has also grown in identifying the factors that underpin high-level outputs. As jump height alone as a variable in evaluating vertical jump performance has been questioned in athletic populations, other variables such as the reactive strength index modified (RSIm) allow for not only evaluating the outcome, but the strategy used in obtaining that outcome. Purpose Thus, the purpose of this investigation was to examine the differences in high and low vertical jump performances, as determined by the RSIm in female collegiate athletes. Methods Thirty NCAA Division I female volleyball and basketball athletes performed countermovement vertical jump trials on a force platform. The sample was then broken into two groups as determined by median RSIm values. Independent sample t-test were then used to compare groups. Results High RSIm group displayed greater jump heights (P < 0.05). Additionally, the high performing group displayed lower eccentric duration times (P < 0.05). No differences between groups were seen in kinetic variables. Conclusion The high performing group displayed faster eccentric times which translated to lower values in time to take-off though not statistical significant. The higher RSIm values appear to be a result of both greater jump heights and reduced time to take off. Thus, focus being placed on the speed of the movement during training would be of benefit in improving RSIm values. PubDate: 2022-11-02
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Abstract: Purpose Main purposes of pre-acclimatization by hypoxia conditioning (HC) are the prevention of high-altitude illnesses and maintenance of aerobic exercise performance. However, robust evidence for those effects or evidence-based guidelines for exposure strategies, including recommendations to ensure safety, are largely lacking. Therefore, we summarize the current knowledge on the physiology of acclimatization to hypoxia and HC with the aim to derive implications for pre-acclimatization strategies before going on high-altitude treks and expeditions. Methods Based on the literature search and personal experience, core studies and important observations have been selected in order to present a balanced view on the current knowledge of high-altitude illnesses and the acclimatization process, specifically focusing on pre-acclimatization strategies by HC. Results and Conclusions It may be concluded that in certain cases even short periods (e.g., 7 h) of pre-acclimatization by HC are effective, but longer periods (e.g., > 60 h) are needed to elicit more robust effects. About 300 h of HC (intermittently applied) may be the optimal preparation for extreme altitude sojourns, although every additional hour spent in hypoxia may confer further benefits. The inclusion of hypobaric exposures (i.e., real altitude) in pre-acclimatization protocols could further increase their efficacy. The level of simulated altitude is progressively increased or individually adjusted ideally. HC should not be terminated earlier than 1–2 weeks before altitude sojourn. Medical monitoring of the pre-acclimatization program is strongly recommended. PubDate: 2022-11-01
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Abstract: Purpose To investigate the effects of 4 weeks high-intensity interval training in hypoxia on aerobic and anaerobic performance of 3-on-3 basketball players. Methods In a randomised controlled trial, 15 female basketballers completed eight 1-h high-intensity training sessions in either normobaric hypoxia (hypoxic group n = 8, altitude 3052 m) or normoxia (normoxic group n = 7, sea-level). Results After training, the hypoxic group increased their 1-min all-out shuttle run distance by 2.5% ± 2.3% (mean ± 95% CI, d = 0.83, P = 0.04), compared to the normoxic group 0.2% ± 2.3% (d = 0.06, P = 0.8), with the difference between groups being clinically worthwhile but not statistically significant (d = 0.77, P = 0.1). Distance covered in the Yo-Yo intermittent recovery test tended to increase in the hypoxic (32.5% ± 39.3%, d = 1.0, P = 0.1) but not normoxic group (0.3% ± 24.5%, d = 0.08, P = 0.9), with a non-significant change between groups (d = 0.9, P = 0.2). Compared to normoxia, the hypoxic group significantly increased subjective markers of stress (d = 0.53, P = 0.005), fatigue (d = 0.43, P = 0.005), and muscle soreness (d = 0.46, P = 0.01), which resulted in a lower perceived training performance in the hypoxic compared to the normoxic group (d = 0.68, P = 0.001). Conclusion High-intensity interval training under hypoxic conditions likely improved 1-min all-out shuttle run ability in female basketball 3-on-3 players but also increased subjective markers of stress and fatigue which must be taken into consideration when prescribing such training. PubDate: 2022-11-01
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Abstract: Abstract Although scientific conclusions remain equivocal, there is evidence-based research, as well as anecdotal support, suggesting that altitude training can enhance performance among Olympic level athletes, particularly in endurance sport. This appears to be due primarily to hypoxia-induced increases in total hemoglobin mass and subsequent improvements in maximal oxygen uptake and other factors contributing to aerobic performance. Although less clear, it is possible that non-hematological adaptations may contribute secondarily to improvements in post-altitude performance. These physiological effects are most likely realized when the altitude exposure is of sufficient “hypoxic dose” to provide the necessary stimuli for performance-affecting changes to occur via hypoxia-inducible factor 1α (HIF-1α) and hypoxia-inducible factor 2α (HIF-2α) pathways and their downstream molecular signaling. Team USA has made a strong commitment over the past 20 years to utilizing altitude training for the enhancement of performance in elite athletes in preparation for the Olympic Games and World Championships. Team USA’s strongest medal-producing Olympic sports—USA Swimming and USA Track and Field—embraced altitude training several years ago, and they continue to be leaders within Team USA in the practical and successful application of altitude training. Whereas USA Swimming utilizes traditional “live high and train high” (LH + TH) altitude training, USA Track and Field tends more toward the use of the altitude training strategy whereby athletes live high (and potentially sleep higher, either naturally or via simulated altitude), while training high during moderate-intensity (< lactate threshold 2) training sessions, and train low during high-intensity (> lactate threshold 2) training sessions (LH + TH[<LT] + TL[>LT]). Although USA Swimming and USA Track and Field have taken different approaches to altitude training, they have been equally successful at the Olympic Games and World Championships, both teams being ranked first in the world based on medals earned in these major international competitions. In addition to USA Swimming and USA Track and Field, several other Team USA sports have had consistently competitive performance results in conjunction with regular and systematic altitude training blocks. The purpose of this paper was to describe select altitude training strategies used by Team USA athletes, and the impact of those strategies on podium performance at major international competitions, specifically the Olympic Games and World Championships. PubDate: 2022-11-01
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Abstract: Abstract Acute exposure to altitude negatively impacts exercise tolerance and reduces athletes’ race performance due to lower atmospheric and body tissues oxygen partial pressures. Chronic exposure to altitude has also been used for several decades by athletes to increase training adaptations. However, the decline in arterial oxygen saturation also impacts 'trainability' and athletes are forced to travel to lower altitude for intensified training. For the athlete preparing for altitude, the advantages of properly timed terrestrial acclimatization and/or sea-level hypoxia-based pre-acclimatization recommendations are clear. However, the associated cost, demands, and time investment make these best-practice strategies difficult or impossible to implement for many athletes. This perspective and opinion article summarizes current knowledge on the potency of ischemic preconditioning (i.e., a sequence of transient ischemic episodes followed by reperfusion) to enhance the pulmonary, vascular, and metabolic determinants of performance at altitude with the aim to derive implications to accelerate or facilitate altitude acclimatization for varied goals. We discuss potential applications for athletes and propose innovative questions for future research in this field. PubDate: 2022-11-01
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Abstract: Purpose The Elevation Training Mask (ETM) has been assessed for its impact on exercise performance using acute and training protocols. Although the ETM is widely available to consumers, little research exists for validation of the ETM mask settings. Therefore, the purpose of this study was to compare physiological responses during exercise for the ETM mask settings against moderate hypobaric hypoxia. Methods Nine participants living at moderate altitude (1600–1650 m) rested (10 min) and cycled in hypobaric hypoxia simulating 2743 m (ALT), in hypobaric hypoxia simulating 1829 m with the ETM set to 914 m (ALT + ETM), and with the ETM set to 2743 m (ETM) in a randomized order. Participants cycled for 20 min at 60% VO2max as determined by a maximal exertion test (VO2max) at baseline altitude. Oxygen consumption was measured throughout each test. Results There were no differences between conditions at rest. Repeated measures ANOVA showed the ALT condition elicited significantly greater VO2 compared to the ETM condition and 60% VO2max at baseline altitude (P < 0.05). Conclusion When cycling at a matched workload, the exercising VO2 was higher in the ALT condition than at the ETM mask setting of 2743 m and exercising VO2 during the ETM condition was similar to 60% VO2max at baseline altitude. The results of this study indicate that the ETM did not produce additional metabolic stress compared to hypobaric hypoxia during steady-state exercise in moderate-altitude living individuals. PubDate: 2022-11-01
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Abstract: Abstract Hypoxia is an essential topic in medical or biological sciences. The main aims of the present study were to examine the most important medical articles (i.e., the top 100 most cited) on hypoxia. We examine how the Nobel-prize awarded hypoxia inducible factor (HIF)-pathway discovery in the early 1990s has changed the thematic composition of this body of literature, with a special emphasis on the studies linking hypoxia and cancer. We searched Pubmed for articles with the terms #Hypox, #Altitude, or #Mountain in the title that have been published in biomedical journals and ranked the articles on their number of citations in Web of Science. A second search was performed in all journals for articles related to hypoxia and cancer. Strikingly, only 12 of the top-100 most-cited articles on hypoxia and only 3 articles of the top-100 articles related to cancer were published before 1995. Moreover, only 5 articles from prior 1995 reached 1000 citations, while 27 articles published in 1995 or later were cited more than 1000 times, most of them on the HIF-1 pathway. Eighty percent of the top-100 articles were related to the HIF pathway, while there were no articles on the application of hypoxia either for therapeutic use (i.e., hypoxic conditioning in patients) or for performance enhancement (i.e., altitude training in athletes). In conclusion, the early-1990s discovery of the HIF pathway and of its molecular regulation has shifted the focus of hypoxia research towards molecular mechanisms and consequences of tissue hypoxia, most notably in cancer. The importance of studies focusing on clinical and performance applications of systemic hypoxia is relatively lower. PubDate: 2022-11-01
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Abstract: Purpose The aim of the present review was to focus on normobaric hypoxic resistance training and to discuss to what extent this method can be efficient for athletes to potentiate classical adaptations to resistance training and thereby performance. Methods Search terms related to the topic of the present review such as normobar*, hypox*, resistance exercise, resistance training and performance were inserted in Pubmed and Scopus. In total, 16 articles made the core of this narrative review. Results Based on the available literature, 2–3 sessions a week performed in hypoxic conditions for 4–6 weeks with a FiO2 of 0.14–0.15 should recommended to athletes looking at potentiating the effects of resistance training. A large range of loads has been found to be efficient at inducing physiological effects in hypoxic vs normoxic conditions, from 20% to 90% of the 1-RM. Ideally, at least the last set should be performed to failure, if not all. Also, inter-set rest periods should be around 30 s for low-load exercise (30%–40% 1-RM), around 60 s for moderate-load exercise (60%–70% 1-RM) and 2 min for high-load exercise (85%–90% 1-RM). Conclusion While there is no one size fits all and certainly no guarantee of added value over normoxic training, each athlete looking at potentiating the effects of resistance training should try to implement some sessions in hypoxic conditions. Based on the individual response, subtle improvements may be expected on muscle strength and mass, velocity and power, as well as hormonal responses to resistance training. PubDate: 2022-11-01
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Abstract: Purpose Elite endurance runners frequently utilise live high-train high (LHTH) altitude training to improve endurance performance at sea level (SL). Individual variability in response to the hypoxic exposure have resulted in contradictory findings. In the present case study, changes in total haemoglobin mass (tHbmass) and physiological capacity, in response to 4-weeks of LHTH were documented. We tested if a hypoxic sensitivity test (HST) could predict altitude-induced adaptations to LHTH. Methods Fifteen elite athletes were selected to complete 4-weeks of LHTH (~ 2400 m). Athletes visited the laboratory for preliminary testing (PRE), to determine lactate threshold (LT), lactate turn point (LTP), maximal oxygen uptake VO2max and tHbmass. During LHTH, athletes completed daily physiological measures [arterial oxygen saturation (SpO2) and body mass] and subjective wellbeing questions. Testing was repeated, for those who completed the full camp, post-LHTH (POST). Additionally, athletes completed the HST prior to LHTH. Results A difference (P < 0.05) was found from PRE to POST in average tHbmass (1.8% ± 3.4%), VO2max (2.7% ± 3.4%), LT (6.1% ± 4.6%) and LTP (5.4% ± 3.8%), after 4-weeks LHTH. HST revealed a decrease in oxygen saturation at rest (ΔSpr) and higher hypoxic ventilatory response at rest (HVRr) predicted individual changes tHbmass. Lower hypoxic cardiac response at rest (HCRr) and higher HVRr predicted individual changes VO2max. Conclusion Four weeks of LHTH at ~ 2400 m increased tHbmass and enhanced physiological capacity in elite endurance runners. There was no observed relationship between these changes and baseline characteristics, pre-LHTH serum ferritin levels, or reported incidents of musculoskeletal injury or illness. The HST did however, estimate changes in tHbmass and VO2max. HST prior to LHTH could allow coaches and practitioners to better inform the acclimatisation strategies and training load application of endurance runners at altitude. PubDate: 2022-11-01
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Abstract: Purpose This study aimed to compare the physical attributes of male and female Volleyball and Beach Volleyball. Methods Fifty-five athletes from Volleyball (Male, n = 19, age 27.3 ± 6.1 years, body mass 93.2 ± 9.9 kg, and height 196.8 ± 7.4 cm and Female, n = 16, age 28.0 ± 5.6 years, body mass 76.9 ± 8.8 kg, and height 179.9 ± 5.8 cm) and Beach Volleyball (Male, n = 10, age 26.8 ± 3.4 years, body mass 92.9 ± 9.9 kg, and height 195.3 ± 7.9 cm and Female, n= 10, age 31.1 ± 6.2 years, body mass 74.6 ± 8.5 kg, and height 180.9 ± 6.0 cm) participated in the study. All tests were performed in a single visit to the laboratory in the following order: body composition, vertical jump (squat and countermovement jump), isokinetic (knees and shoulders), and cardiopulmonary exercise testing. All variables were analyzed using a two-way ANOVA (Sex and Sport factors) for independent groups. Results Beach Volleyball athletes presented lower body fat (P = 0.03; ES = 0.32) and higher maximal cardiorespiratory variables (VO2, HR, and vVO2max). Only flexion bilateral difference (knee) at 60°/s was affected by sex (P = 0.002; ES = 0.63). For shoulders, only dominant external/internal rotation ratio presented a significant interaction for sport and sex (P = 0.05; ES = 0.28). Regarding vertical jumps, Volleyball male players presented a greater elastic index than BV male players (P = 0.002, ES = 0.67). Conclusion Beach Volleyball players are thinner and have better cardiorespiratory fitness than Volleyball players. Also, they presented less use of elastic properties for vertical jumping and have a greater muscle imbalance in the hamstrings than Volleyball players. PubDate: 2022-10-24
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