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MEDICAL SCIENCES (2415 journals)            First | 3 4 5 6 7 8 9 10 | Last

Showing 1201 - 1400 of 3562 Journals sorted alphabetically
Journal of Evaluation In Clinical Practice     Hybrid Journal   (Followers: 6)
Journal of Evidence-Based Healthcare     Open Access   (Followers: 1)
Journal of Evidence-Based Integrative Medicine     Open Access   (Followers: 18)
Journal of Evidence-Based Medicine     Partially Free   (Followers: 4)
Journal of Exercise Science & Fitness     Open Access   (Followers: 29)
Journal of Experimental and Clinical Anatomy     Open Access   (Followers: 2)
Journal of Family and Community Medicine     Open Access   (Followers: 3)
Journal of Family Medicine and Primary Care     Open Access   (Followers: 11)
Journal of Foot and Ankle Research     Open Access   (Followers: 6)
Journal of Forensic Science and Research     Open Access   (Followers: 2)
Journal of Gandaki Medical College-Nepal     Open Access  
Journal of Generic Medicines     Hybrid Journal   (Followers: 2)
Journal of Geographical Sciences     Hybrid Journal   (Followers: 1)
Journal of Global Antimicrobial Resistance     Hybrid Journal   (Followers: 3)
Journal of Hand Therapy     Hybrid Journal   (Followers: 19)
Journal of Head & Neck Physicians and Surgeons     Open Access   (Followers: 2)
Journal of Health & Medical Informatics     Open Access   (Followers: 62)
Journal of Health and Biological Sciences     Open Access   (Followers: 1)
Journal of Health Design     Open Access   (Followers: 1)
Journal of Health Economics and Outcomes Research     Open Access   (Followers: 1)
Journal of Health Promotion and Behavior     Open Access  
Journal of Health Research and Reviews     Open Access  
Journal of Health Science and Medical Research     Open Access  
Journal of Health Science Research     Open Access  
Journal of Health Sciences     Open Access   (Followers: 1)
Journal of health sciences     Open Access  
Journal of Health Sciences / Sağlık Bilimleri Dergisi     Open Access  
Journal of Health Sciences and Medicine     Open Access  
Journal of Health Sciences and Medicine     Open Access   (Followers: 6)
Journal of Health Sciences and Surveillance System     Open Access  
Journal of Health Sciences Scholarship     Open Access  
Journal of Health Specialties     Open Access  
Journal of Health Studies     Open Access  
Journal of Healthcare Informatics Research     Hybrid Journal   (Followers: 1)
Journal of Heavy Metal Toxicity and Diseases     Open Access  
Journal of Helminthology     Hybrid Journal   (Followers: 2)
Journal of Herbs Spices & Medicinal Plants     Hybrid Journal  
Journal of HIV for Clinical and Scientific Research     Open Access   (Followers: 2)
Journal of Hospital Medicine     Hybrid Journal   (Followers: 11)
Journal of Huazhong University of Science and Technology [Medical Sciences]     Hybrid Journal  
Journal of Human Hypertension     Hybrid Journal   (Followers: 3)
Journal of Human Rhythm     Open Access  
Journal of Human Transcriptome     Open Access  
Journal of Ideas in Health     Open Access  
Journal of Inflammation     Open Access   (Followers: 2)
Journal of Inflammation Research     Open Access  
Journal of Injury and Violence Research     Open Access   (Followers: 6)
Journal of Innovation in Health Informatics     Open Access   (Followers: 17)
Journal of Institute of Medicine     Open Access  
Journal of Insulin Resistance     Open Access   (Followers: 1)
Journal of Interactional Research in Communication Disorders     Hybrid Journal   (Followers: 5)
Journal of Interferon & Cytokine Research     Hybrid Journal   (Followers: 3)
Journal of International Medical Research     Open Access   (Followers: 3)
Journal of Interventional Medicine     Open Access   (Followers: 1)
Journal of Investigative Medicine     Hybrid Journal   (Followers: 3)
Journal of Islamabad Medical & Dental College     Open Access   (Followers: 2)
Journal of Istanbul Faculty of Medicine     Open Access  
Journal of Karnali Academy of Health Sciences     Open Access   (Followers: 1)
Journal of Kathmandu Medical College     Open Access   (Followers: 1)
Journal of King Abdulaziz University : Medical Sciences     Open Access   (Followers: 2)
Journal of Laboratory Medicine     Hybrid Journal   (Followers: 27)
Journal of Laryngology and Voice     Open Access   (Followers: 11)
Journal of Lasers in Medical Sciences     Open Access  
Journal of Law, Medicine & Ethics     Hybrid Journal   (Followers: 28)
Journal of Legal Medicine     Hybrid Journal   (Followers: 7)
Journal of Limb Lengthening & Reconstruction     Open Access  
Journal of Lumbini Medical College     Open Access   (Followers: 1)
Journal of Mahatma Gandhi Institute of Medical Sciences     Open Access  
Journal of Manipulative and Physiological Therapeutics     Hybrid Journal   (Followers: 6)
Journal of Manmohan Memorial Institute of Health Sciences     Open Access   (Followers: 1)
Journal of Marine Medical Society     Open Access  
Journal of Materials Science : Materials in Medicine     Hybrid Journal   (Followers: 4)
Journal of Maternal and Child Health     Open Access  
Journal of Mechanics in Medicine and Biology     Hybrid Journal  
Journal of Medical and Biological Engineering     Hybrid Journal   (Followers: 4)
Journal of Medical and Biomedical Sciences     Open Access   (Followers: 2)
Journal of Medical Case Reports     Open Access   (Followers: 1)
Journal of Medical Cases     Open Access   (Followers: 6)
Journal of Medical Colleges of PLA     Full-text available via subscription  
Journal of Medical Disorders     Open Access  
Journal of Medical Economics     Hybrid Journal   (Followers: 8)
Journal of Medical Education and Curricular Development     Open Access   (Followers: 6)
Journal of Medical Ethics     Partially Free   (Followers: 27)
Journal of Medical Ethics and History of Medicine     Open Access   (Followers: 19)
Journal of Medical Humanities     Hybrid Journal   (Followers: 21)
Journal of Medical Hypotheses and Ideas     Open Access  
Journal of Medical Imaging and Health Informatics     Full-text available via subscription   (Followers: 1)
Journal of Medical Investigation and Practice     Open Access  
Journal of Medical Laboratory and Diagnosis     Open Access  
Journal of Medical Law and Ethics     Full-text available via subscription   (Followers: 17)
Journal of Medical Microbiology     Full-text available via subscription   (Followers: 6)
Journal of Medical Sciences     Open Access  
Journal of Medical Sciences     Open Access  
Journal of Medical Screening     Hybrid Journal   (Followers: 6)
Journal of Medical Signals and Sensors     Open Access   (Followers: 3)
Journal of Medical Society     Open Access  
Journal of Medical Systems     Hybrid Journal  
Journal of Medical Toxicology     Hybrid Journal   (Followers: 6)
Journal of Medical Ultrasound     Open Access   (Followers: 2)
Journal of Medicinal Botany     Open Access  
Journal of Medicinal Chemistry     Hybrid Journal   (Followers: 207)
Journal of Medicine     Open Access   (Followers: 1)
Journal of Medicine and Biomedical Research     Open Access   (Followers: 1)
Journal of Medicine and Philosophy     Hybrid Journal   (Followers: 9)
Journal of Medicine and the Person     Hybrid Journal  
Journal of Medicine in Scientific Research     Open Access  
Journal of Medicine in the Tropics     Open Access  
Journal of Medicine Research and Development     Open Access   (Followers: 3)
Journal of Medicine, Physiology and Biophysics     Open Access   (Followers: 5)
Journal of Medicines Development Sciences     Open Access   (Followers: 1)
Journal of Metabolomics & Systems Biology     Open Access   (Followers: 2)
Journal of Mind and Medical Sciences     Open Access   (Followers: 1)
Journal of Molecular Medicine     Hybrid Journal   (Followers: 11)
Journal of Movement Disorders     Open Access   (Followers: 2)
Journal of Multidisciplinary Research in Healthcare     Open Access   (Followers: 2)
Journal of Muscle Research and Cell Motility     Hybrid Journal   (Followers: 1)
Journal of Nanotechnology in Engineering and Medicine     Full-text available via subscription   (Followers: 6)
Journal of Nanotheranostics     Open Access   (Followers: 1)
Journal of Natural Medicines     Hybrid Journal  
Journal of Natural Science, Biology and Medicine     Open Access   (Followers: 3)
Journal of Nature and Science of Medicine     Open Access   (Followers: 4)
Journal of Negative and No Positive Results     Open Access  
Journal of Nepalgunj Medical College     Open Access  
Journal of Neurocritical Care     Open Access  
Journal of Neurodegenerative Diseases     Open Access   (Followers: 2)
Journal of Neurorestoratology     Open Access  
Journal of Neuroscience and Neurological Disorders     Open Access  
Journal of Nobel Medical College     Open Access  
Journal of Obesity and Bariatrics     Open Access   (Followers: 2)
Journal of Occupational Health     Open Access  
Journal of Occupational Therapy Education     Open Access   (Followers: 12)
Journal of Ocular Biology, Diseases, and Informatics     Hybrid Journal  
Journal of Oral Biology and Craniofacial Research     Full-text available via subscription  
Journal of Oral Health and Craniofacial Science     Open Access  
Journal of Orofacial Sciences     Open Access  
Journal of Otorhinolaryngology, Hearing and Balance Medicine     Open Access   (Followers: 1)
Journal of Ovarian Research     Open Access  
Journal of Ozone Therapy     Open Access  
Journal of Palliative Medicine     Hybrid Journal   (Followers: 47)
Journal of Paramedical Sciences & Rehabilitation     Open Access  
Journal of Parkinsonism and Restless Legs Syndrome     Open Access   (Followers: 2)
Journal of Parkinson’s Disease and Alzheimer’s Disease     Open Access   (Followers: 1)
Journal of Participatory Medicine     Open Access  
Journal of Patan Academy of Health Sciences     Open Access  
Journal of Pathogens     Open Access   (Followers: 1)
Journal of Patient Experience     Open Access  
Journal of Patient Safety and Risk Management     Hybrid Journal   (Followers: 2)
Journal of Patient-Centered Research and Reviews     Open Access  
Journal of Patient-Reported Outcomes     Open Access  
Journal of Periodontal Research     Hybrid Journal  
Journal of Personalized Medicine     Open Access   (Followers: 3)
Journal of Pest Science     Hybrid Journal   (Followers: 1)
Journal of Pharmaceutical Policy and Practice     Open Access   (Followers: 4)
Journal of Physiobiochemical Metabolism     Hybrid Journal   (Followers: 2)
Journal of Physiology-Paris     Hybrid Journal   (Followers: 2)
Journal of Pioneering Medical Sciences     Open Access  
Journal of Postgraduate Medicine     Open Access  
Journal of Pregnancy     Open Access   (Followers: 4)
Journal of Prevention & Intervention Community     Hybrid Journal   (Followers: 7)
Journal of Preventive Medicine and Public Health     Open Access  
Journal of Primary Prevention     Hybrid Journal   (Followers: 7)
Journal of Prosthodontic Research     Full-text available via subscription   (Followers: 1)
Journal of Prosthodontics     Hybrid Journal   (Followers: 2)
Journal of Receptor, Ligand and Channel Research     Open Access   (Followers: 1)
Journal of Regenerative Medicine     Partially Free   (Followers: 4)
Journal of Research in Medical Sciences     Open Access   (Followers: 2)
Journal of Science and Applications : Biomedicine     Open Access   (Followers: 1)
Journal of Science and Technology (Ghana)     Open Access   (Followers: 3)
Journal of Scientific Innovation in Medicine     Open Access  
Journal of Scientific Perspectives     Open Access   (Followers: 1)
Journal of Sensory Studies     Hybrid Journal   (Followers: 4)
Journal of Shaheed Suhrawardy Medical College     Open Access  
Journal of Shoulder and Elbow Arthroplasty     Open Access  
Journal of Sleep Disorders : Treatment & Care     Hybrid Journal   (Followers: 10)
Journal of South American Earth Sciences     Hybrid Journal   (Followers: 5)
Journal of Spinal Cord Medicine     Hybrid Journal   (Followers: 5)
Journal of Spinal Disorders & Techniques     Hybrid Journal   (Followers: 2)
Journal of Sports Medicine and Allied Health Sciences : Official Journal of the Ohio Athletic Trainers Association     Open Access   (Followers: 1)
Journal of Stem Cell Therapy and Transplantation     Open Access   (Followers: 1)
Journal of Stomal Therapy Australia     Full-text available via subscription   (Followers: 1)
Journal of Strength and Conditioning Research     Hybrid Journal   (Followers: 77)
Journal of Substance Use     Hybrid Journal   (Followers: 15)
Journal of Surgical Academia     Open Access   (Followers: 1)
Journal of Surgical and Clinical Research     Open Access  
Journal of Surgical Case Reports     Open Access  
Journal of Surgical Education     Full-text available via subscription   (Followers: 3)
Journal of Surgical Technique and Case Report     Open Access  
Journal of Systemic Therapies     Full-text available via subscription   (Followers: 3)
Journal of Taibah University Medical Sciences     Open Access  
Journal of Telemedicine and Telecare     Hybrid Journal   (Followers: 12)
Journal of The Academy of Clinical Microbiologists     Open Access  
Journal of the American Association for Laboratory Animal Science     Full-text available via subscription   (Followers: 9)
Journal of the American College of Certified Wound Specialists     Hybrid Journal   (Followers: 2)
Journal of the American College of Clinical Wound Specialists     Hybrid Journal   (Followers: 2)
Journal of the American Medical Directors Association     Hybrid Journal   (Followers: 5)
Journal of the American Medical Informatics Association : JAMIA     Hybrid Journal   (Followers: 36)
Journal of the American Podiatric Medical Association     Full-text available via subscription   (Followers: 7)
Journal of the Anatomical Society of India     Full-text available via subscription  
Journal of the Anus, Rectum and Colon     Open Access  
Journal of The Arab Society for Medical Research     Open Access  

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Similar Journals
Journal Cover
Journal of Strength and Conditioning Research
Journal Prestige (SJR): 1.366
Citation Impact (citeScore): 2
Number of Followers: 77  
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1064-8011 - ISSN (Online) 1533-4287
Published by LWW Wolters Kluwer Homepage  [301 journals]
  • Decline in Unintentional Lifting Velocity Is Both Load and Exercise
    • Authors: Beck; Maddison; Varner, William; LeVault, Lindsay; Boring, Johnathan; Fahs, Christopher A.
      Abstract: imageBeck, M, Varner, W, LeVault, L, Boring, J, and Fahs, CA. Decline in unintentional lifting velocity is both load and exercise specific. J Strength Cond Res 34(10): 2709–2714, 2020—When monitoring the mean concentric velocity (MCV) for velocity-based resistance training, often a threshold in the decline in the MCV is used to regulate the number of repetitions performed. However, it is not clear if the decline in the MCV is affected by the type of exercise or the relative load used. Therefore, the purpose of this study was to compare the decline in the MCV between the overhead press (OHP) and deadlift (DL) during sets to fatigue at different loads. Thirty individuals (23 ± 3 years) with current training experience with both the OHP and DL completed a 1 repetition maximum (1RM) protocol for the OHP and DL. Subjects then returned to the laboratory on 2 separate occasions and completed 1 set of the OHP and DL to volitional fatigue at either 70 or 90% of their 1RM in a randomized order. The open barbell system measured the MCV of all repetitions. The absolute and relative (%) decline in the MCV was calculated for each condition and compared between loads (70 vs. 90% 1RM) and between lifts (OHP vs. DL). An alpha level of 0.05 was used at the criterion for statistical significance. The absolute decline in the MCV was greatest for the 70% OHP condition (0.36 ± 0.12 m·s−1) followed by 90% OHP (0.19 ± 0.10 m·s−1), 70% DL (0.16 ± 0.08 m·s−1), and 90% DL (0.09 ± 0.06 m·s−1); all were significantly different from one another (p < 0.05) except for 70% DL vs. 90% OHP (p = 0.441). There was a greater relative decline in the MCV for the OHP compared with the DL (50.1 ± 11.8% vs. 28.5 ± 11.8%; p < 0.001) and for 70% 1RM compared with 90% 1RM (44.5 ± 12.0% vs. 34.1 ± 12.0%; p < 0.001). These data suggest the decline in the MCV is both exercise and load specific. Applying a uniform velocity decline threshold for velocity-based training may reduce training volume to different extents depending on the exercise and relative load used.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Kinetic and Electromyographic Responses to Traditional and Assisted Nordic
           Hamstring Exercise
    • Authors: Burrows; Adam P.; Cleather, Dan; Mahaffey, Ryan; Cimadoro, Giuseppe
      Abstract: imageBurrows, AP, Cleather, D, Mahaffey, R, and Cimadoro, G. Kinetic and electromyographic responses to traditional and assisted Nordic hamstring exercise. J Strength Cond Res 34(10): 2715–2724, 2020—The Nordic hamstring exercise (NHE) is performed to increase hamstring strength, elicit morphological changes, and reduce injury risk. However, to date, the NHE assisted by the means of an external resistance has not been investigated. Thus, this study compared the eccentric knee flexor strength, rating of perceived exertion (RPE), and electromyographic responses of the biceps femoris (BF) and semitendinosus (ST) when performing the NHE under assisted or unassisted conditions. Sixteen professional soccer players (aged 19.4 ± 2.2 years) performed 5 sets of 3 NHE unassisted and with assisting loads (5–20% of the body mass) using the Keiser machine. Eccentric knee flexor strength was measured from the subjects' dominant limb. Peak surface electromyography (sEMG) of the BF and ST was recorded from the dominant limb; the ratio was also calculated. Subjects rated the intensity of each condition of the NHE on a ten-point RPE Borg scale. All assisted conditions displayed significantly lower (p < 0.05) absolute and relative eccentric knee flexor strength than unassisted conditions. Rating of perceived exertion for each loading condition was significantly lower (p < 0.05) as the assisting load increased except for the difference between the 10 and 15% assisted conditions. Surface electromyography of the BF and ST was not significantly lower (p < 0.05) during all assisted conditions compared with the unassisted NHE, neither there were significant between-muscle differences or sEMG ratios. Our findings suggest that the assisted NHE reduces the load and difficulty of the exercise. Practitioners can use the assisted NHE to manipulate intensity and difficulty if that is appropriate for their programming.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Acute Neuromuscular and Microvascular Responses to Concentric and
           Eccentric Exercises With Blood Flow Restriction
    • Authors: Lauver; Jakob D.; Cayot, Trent E.; Rotarius, Timothy R.; Scheuermann, Barry W.
      Abstract: imageLauver, JD, Cayot, TE, Rotarius, TR, and Scheuermann, BW. Acute neuromuscular and microvascular responses to concentric and eccentric exercises with blood flow restriction. J Strength Cond Res 34(10): 2725–2733, 2020—The purpose of this study was to investigate the effects of the addition of blood flow restriction (BFR) during concentric and eccentric exercises on muscle excitation and microvascular oxygenation status. Subjects (N = 17) were randomly assigned to either a concentric (CON, CON + BFR) or eccentric (ECC, ECC + BFR) group, with one leg assigned to BFR and the other to non-BFR. Surface electromyography and near-infrared spectroscopy were used to measure muscle excitation and microvascular deoxygenation (deoxy-[Hb + Mb]) and [total hemoglobin concentration] during each condition, respectively. On separate days, subjects completed 4 sets (30, 15, 15, 15) of knee extension exercise at 30% maximal torque, and 1 minute of rest was provided between the sets. Greater excitation of the vastus medialis was observed during CON + BFR (54.4 ± 13.3% maximal voluntary isometric contraction [MVIC]) and ECC + BFR (53.0 ± 18.0% MVIC) compared with CON (42.0 ± 10.8% MVIC) and ECC (46.8 ± 9.6% MVIC). Change in deoxy-[Hb + Mb] was greater during CON + BFR (10.0 ± 10.4 μM) than during CON (4.1 ± 4.0 μM; p < 0.001). ECC + BFR (7.8 ± 6.7 μM) was significantly greater than ECC (3.5 ± 4.7 μM; p = 0.001). Total hemoglobin concentration was greater for ECC + BFR (7.9 ± 4.4 μM) compared with ECC (5.5 ± 3.5 μM). The addition of BFR to eccentric and concentric exercises resulted in a significant increase in metabolic stress and muscle excitation compared with non-BFR exercise. These findings suggest that although BFR may increase the hypertrophic stimulus during both modes of contraction, BFR during concentric contractions may result in a greater stimulus.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Changes in Bench Press Velocity and Power After 8 Weeks of High-Load
           Cluster- or Traditional-Set Structures
    • Authors: Davies; Timothy B.; Halaki, Mark; Orr, Rhonda; Helms, Eric R.; Hackett, Daniel A.
      Abstract: imageDavies, TB, Halaki, M, Orr, R, Helms, ER, and Hackett, DA. Changes in bench press velocity and power after 8 weeks of high-load cluster- or traditional-set structures. J Strength Cond Res 34(10): 2734–2742, 2020—This study investigated the effects of high-load cluster- vs. traditional-set structures using the bench press on velocity and power. Twenty-one resistance-trained individuals (male = 12, female = 9) performed a 3-week familiarization block followed by randomization into 1 of 2 upper- and lower-body split training routines performed for 8 weeks. The bench press was the only exercise manipulated with subjects using either cluster-set (CLUS, n = 11) or traditional-set (TRAD, n = 10) structures during training sessions. Subjects performed 4 sets of 5 repetitions at 85% 1 repetition maximum (1RM) with CLUS having a 30-second inter-repetition, and 3-minute interset rest while TRAD had a 5-minute interset rest. A load-velocity profile of relative loads derived from a 1RM test was used to assess velocity and power (absolute and relative to body mass) on the bench press. Significant improvements over time were found across various loads ranging from 45 to 75% 1RM for absolute and relative peak power (p = 0.006–0.041), and mean power (p = 0.001–0.032). Significant decreases over time were found at 55% 1RM and 65% 1RM for peak velocity (p = 0.027 and p = 0.012, respectively) and mean velocity (p = 0.047 and p = 0.022, respectively). There were no significant group or group by time interactions found for all outcomes. Within the context of high-load resistance training, set structure seems to be of less importance for changes in bench press velocity and power provided there is an intention to lift with maximal concentric velocity.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Effects of Short-Term Unilateral Strength Training on Measures of Postural
           Control When Wearing “Operationally Relevant” Backpack Loads
    • Authors: Krajewski; Kellen T.; Bansbach, Heather M.; McLean, Lucy; McKenzie, Clive; Rawcliffe, Alex; Graham, Scott M.; Flanagan, Shawn D.; Pourmoghaddam, Amir; Dettmer, Marius; Connaboy, Chris
      Abstract: imageKrajewski, KT, Bansbach, HM, McLean, L, McKenzie, C, Rawcliffe, A, Graham, SM, Flanagan, SD, Pourmoghaddam, A, Dettmer, M, and Connaboy, C. Effects of short-term unilateral strength training on measures of postural control when wearing “operationally relevant” backpack loads. J Strength Cond Res 34(10): 2743–2750, 2020—To examine the effects of “operationally relevant” loads on postural stability and to determine the effects of unilateral and bilateral strength training programs on postural stability in healthy, recruit-aged men. Fifteen subjects were randomly assigned to either a unilateral (UL; n = 7) or bilateral (BL; n = 8) strength training group, which performed strength training 3 times a week for 4 weeks. Subjects completed the following pretest and post-test assessments: 1 repetition maximum in bilateral (1RM-BL) and unilateral (1RM-UL) stance positions and bilateral and unilateral balance tasks with eyes open and eyes closed. Balance tasks were performed over 3 loading conditions: body mass (BM), 50% BM, and 70% BM. Sample entropy (SE) and root mean square (RMS) were calculated from the center of pressures collected during each balance assessment. The UL strength training group showed significant improvement after training in both 1RM-UL (p < 0.01) and 1RM-BL (p < 0.01). The BL strength training group only showed significant improvement in 1RM-BL (p = 0.01). There was a significant main effect of load on RMS (p < 0.05) across all balance tasks with RMS increasing with increasing load. Sample entropy was found to decrease with increasing load in the unilateral eyes open and bilateral stance tasks. Significant increases in strength (∼10 to –29%) were observed; however, increased strength alone is not enough to mitigate the effects of load carriage on the postural control, even when training is performed in stance positions that are posturally challenging. Therefore, “operationally relevant” loads negatively impact postural stability in novice load carriers when assessing nonlinear measures.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Influence of Resisted Sled-Pull Training on the Sprint Force-Velocity
           Profile of Male High-School Athletes
    • Authors: Cahill; Micheál J.; Oliver, Jon L.; Cronin, John B.; Clark, Kenneth; Cross, Matt R.; Lloyd, Rhodri S.; Lee, Jeong E.
      Abstract: imageCahill, MJ, Oliver, JL, Cronin, JB, Clark, K, Cross, MR, Lloyd, RS, and Lee, JE. Influence of resisted sled-pull training on the sprint force-velocity profile of male high-school athletes. J Strength Cond Res 34(10): 2751–2759, 2020—Although resisted sled towing is a commonly used method of sprint-specific training, little uniformity exists around training guidelines for practitioners. The aim of this study was to assess the effectiveness of unresisted and resisted sled-pull training across multiple loads. Fifty-three male high-school athletes were assigned to an unresisted (n = 12) or 1 of 3 resisted groups: light (n = 15), moderate (n = 14), and heavy (n = 12) corresponding to loads of 44 ± 4 %BM, 89 ± 8 %BM, and 133 ± 12 %BM that caused a 25, 50, and 75% velocity decrement in maximum sprint speed, respectively. All subjects performed 2 sled-pull training sessions twice weekly for 8 weeks. Split times of 5, 10, and 20 m improved across all resisted groups (d = 0.40–1.04, p < 0.01) but did not improve with unresisted sprinting. However, the magnitude of the gains increased most within the heavy group, with the greatest improvement observed over the first 10 m (d ≥ 1.04). Changes in preintervention to postintervention force-velocity profiles were specific to the loading prescribed during training. Specifically, F0 increased most in moderate to heavy groups (d = 1.08–1.19); Vmax significantly decreased in the heavy group but increased in the unresisted group (d = 012–0.44); whereas, Pmax increased across all resisted groups (d = 0.39–1.03). The results of this study suggest that the greatest gains in short distance sprint performance, especially initial acceleration, are achieved using much heavier sled loads than previously studied in young athletes.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Effects of Maturation on Physical Fitness Adaptations to Plyometric Drop
           Jump Training in Male Youth Soccer Players
    • Authors: Vera-Assaoka; Tiago; Ramirez-Campillo, Rodrigo; Alvarez, Cristian; Garcia-Pinillos, Felipe; Moran, Jason; Gentil, Paulo; Behm, David
      Abstract: imageVera-Assaoka, T, Ramirez-Campillo, R, Alvarez, C, Garcia-Pinillos, F, Moran, J, Gentil, P, and Behm, D. Effects of maturation on physical fitness adaptations to plyometric drop jump training in male youth soccer players. J Strength Cond Res 34(10): 2760–2768, 2020—The objective of this study was to compare the effects of maturation on physical fitness adaptations to a twice weekly, 7-week plyometric drop jump training program. Seventy-six young male soccer players (aged 10–16 years) participated in this randomized controlled trial. Before and after the intervention, a physical fitness test battery was applied (countermovement jump; drop jump from 20 to 40 cm; 5 multiple bounds test; 20-m sprint time; change of direction speed; 2.4-km running time-trial; 5 repetition maximum [RM] squat; and maximal kicking distance). Participants were randomly divided into an active soccer-control group (CG) with Tanner stage maturation of 1–3 (CG-early; n = 16) or Tanner stage 4–5 (CG-late; n = 22), and to plyometric drop jump training groups with Tanner stage 1–3 (plyometric jump training [PJT]-early; n = 16) or 4–5 (PJT-late; n = 22). The analysis of variance and effect size (ES) measures revealed that when compared with their age-matched controls, the PJT-early (ES = 0.39–1.58) and PJT-late (ES = 0.21–0.65) groups showed greater improvements (p < 0.05) in sprint time, 2.4-km running time-trial, change of direction speed, 5RM squat, jumping, and kicking distance. The PJT-early exceeded the PJT-late group with greater (p < 0.05) improvements in drop jump from 20 cm (ES = 1.58 vs. 0.51) and 40 cm (ES = 0.71 vs. 0.4) and kicking distance (ES = 0.95 vs. 0.65). Therefore, a 7-week plyometric drop jump training program was effective in improving physical fitness traits in both younger and older male youth soccer players, with greater jumping and kicking adaptations in the less-mature athletes.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Survey of Eccentric-Based Strength and Conditioning Practices in Sport
    • Authors: McNeill; Conor; Beaven, Christopher Martyn; McMaster, Daniel T.; Gill, Nicholas
      Abstract: imageMcNeill, C, Beaven, CM, McMaster, DT, and Gill, N. Survey of eccentric-based strength and conditioning practices in sport. J Strength Cond Res 34(10): 2769–2775, 2020—Eccentric-based training (ECC) has been shown to be an effective training strategy in athletes; however, despite the theoretical benefits, the uptake by practitioners is currently unknown. This study investigated the current ECC strength and conditioning practices that are implemented in the training of athletes. Two hundred twenty-four practitioners were electronically surveyed anonymously with 98 responses available for analysis. Nearly all respondents (96%) had prescribed ECC in the last 24 months. Sport performance (64%), injury prevention (24%), and rehabilitation (8%) were the top-ranked reasons to include ECC. Respondents programmed ECC for strength (35%), hypertrophy (19%), and power (18%). A majority of respondents did not monitor ECC load (58%) or use eccentric-specific testing (75%). Seventeen respondents commented that high-intensity training such as sprinting and change of direction, were avoided during ECC blocks. Eccentric-based training intensity was prescribed as percentage of 1 repetition maximum (34%), rate of perceived exertion (20%), or velocity (16%). Respondents indicated muscle soreness and concurrent high-intensity activities were concerns during ECC but reported not using eccentric monitoring or testing. The efficacy of ECC is well supported, yet there seems to be a lack of defined protocol for integrating ECC research into practice. A greater understanding of eccentric contribution to sport performance and injury prevention may help define testing and monitoring procedures for the prescription of ECC interventions. Practitioners should consider factors such as periodization, soreness, and monitoring when designing ECC programs. The findings of this survey indicate that no uniform strategies exist for the prescription of ECC among experienced practitioners.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • The Effect of a Neuromuscular vs. Dynamic Warm-up on Physical Performance
           in Young Tennis Players
    • Authors: Fernandez-Fernandez; Jaime; García-Tormo, Vicente; Santos-Rosa, Francisco Javier; Teixeira, Anderson Santiago; Nakamura, Fábio Yuzo; Granacher, Urs; Sanz-Rivas, David
      Abstract: imageFernandez-Fernandez, J, García-Tormo, V, Santos-Rosa, FJ, Teixeira, AS, Nakamura, FY, Granacher, U, and Sanz-Rivas, D. The effect of a neuromuscular vs. dynamic warm-up on physical performance in young tennis players. J Strength Cond Res 34(10): 2776–2784, 2020—The aim of this study was to examine performance-enhancing (i.e., training) effects of a neuromuscular warm-up (NWU) compared with a dynamic WU (DWU) in young tennis players. Twenty-eight well-trained male tennis players with a mean age of 15.09 ± 1.16 years participated in this study and were assigned to either a training group performing NWU (n = 14), or a group that followed DWU (n = 15) before tennis-specific training, for 8 weeks. Pretest and posttest included: speed (5, 10, and 20 m); modified 5-0-5 change of direction (COD) test; bilateral/unilateral countermovement jump (CMJ); 2 kg overhead, forehand, and backhand-side medicine ball throw performance (MBT); serve velocity, and shoulder strength and range-of-motion (ROM) performance (i.e., internal [IR]/external [ER] rotation). Results showed that both groups, NWU and DWU, significantly improved their sprint performances (5–20 m; [p < 0.05; d = 0.83–1.32]), CMJ (bilateral and unilateral [dominant side] [p < 0.005; d = 1.27–1.59]), overhead MBT (p = 0.014; d = 1.02), and some shoulder strength (i.e., IR dominant side [D], ER D, ER/IR ratio [p < 0.05; d = 0.86–1.59]) and ROM (i.e., ER D, total ROM D [p < 0.05; d = 0.80–1.02]) values. However, the interaction effects revealed that NWU compared with DWU produced greater performance gains in most of the analyzed parameters (i.e., 5–10 m sprint, CMJ, overhead MBT, serve speed). The inclusion of an NWU characterized by a relatively low volume (∼20–35 minutes), including general mobility, core, and shoulder strength exercises, combined with neuromuscular-related exercises (e.g., plyometric and acceleration/deceleration/COD drills), can be recommended to obtain positive effects in tennis performance-related variables.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • A 28-Day Carbohydrate-Restricted Diet Improves Markers of Cardiovascular
           Disease in Professional Firefighters
    • Authors: Waldman; Hunter S.; Smith, JohnEric W.; Lamberth, John; Fountain, Brent J.; Bloomer, Richard J.; Butawan, Matthew B.; McAllister, Matthew J.
      Abstract: imageWaldman, HS, Smith, JW, Lamberth, J, Fountain, BJ, Bloomer, RJ, Butawan, MB, and McAllister, MJ. A 28-day carbohydrate-restricted diet improves markers of cardiovascular disease in professional firefighters. J Strength Cond Res 34(10): 2785–2792, 2020—This study compared the effects of a 4-week, nonketogenic, carbohydrate-restricted (
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Using the Session Rating of Perceived Exertion to Quantify Training Load
           in a Men's College Soccer Team
    • Authors: Sams; Matt L.; Wagle, John P.; Sato, Kimitake; DeWeese, Brad H.; Sayers, Adam L.; Stone, Michael H.
      Abstract: imageSams, ML, Wagle, JP, Sato, K, DeWeese, BH, Sayers, AL, and Stone, MH. Using the session rating of perceived exertion to quantify training load in a men's college soccer team. J Strength Cond Res 34(10): 2793–2799, 2020—The purpose of this study was to examine the training load (TL) programming of 3 training groups of a National Collegiate Athletic Association Division I men's college soccer team across a season. Thirty athletes were classified as starters (S), substitutes (NS), or redshirts (RS) based on the percentage of possible minutes played during the season. Training load was quantified at the season, phasic, and weekly levels by the session rating of perceived exertion. Between-group differences were observed at the season level (p < 0.001), and group-by-time interactions for average weekly TL were found at both the phasic (p = 0.04) and weekly levels (p < 0.001). In general, S accumulated greater TL than NS (effect size range for all analyses: −0.59 < d < 1.91) and RS (0.17 < d < 3.67), and NS accumulated greater TL than RS (−0.54 < d < 2.34). Within-group variation at the phasic level was less apparent (−0.35 < d < 1.44); however, all 3 groups displayed training variation at the weekly level (−1.80 < d < 3.24). The session rating of perceived exertion can serve as a low-cost, valid means of quantifying TL in men's college soccer athletes. Practitioners should be especially aware of the possibility of insufficient loading in NS.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Relationship Between the Session-RPE and External Measures of Training
           Load in Youth Soccer Training
    • Authors: Marynowicz; Jakub; Kikut, Karol; Lango, Mateusz; Horna, Damian; Andrzejewski, Marcin
      Abstract: imageMarynowicz, J, Kikut, K, Lango, M, Horna, D, and Andrzejewski, M. Relationship between the session-RPE and external measures of training load in youth soccer training. J Strength Cond Res 34(10): 2800–2804, 2020—The aim of this study was to identify the external training load (TL) markers (10 Hz Global Positioning System) that are most influential on the rating of perceived exertion (RPE) and session-RPE (sRPE) during youth soccer training. Data were collected from 18 youth soccer players during an 18-week in-season period. A total of 804 training observations were undertaken. We observed moderate to very large within-individual correlations between sRPE and measures of external load (r ranging from 0.36 to 0.76). Large, positive within-individual correlations were found between total covered distance, PlayerLoad, number of accelerations, and sRPE (r = 0.70, 0.64, and 0.62, respectively, p < 0.001). By contrast, small to moderate within-individual correlations were noted between RPE and measures of intensity (r ranging from 0.16 to 0.39). A moderate within-individual correlation was observed between high-speed running distance (HSR) per minute and RPE (r = 0.39, p < 0.001). The level of statistical significance was set at alpha = 0.05 for all tests. Two generalized estimating equation models were constructed, with RPE and sRPE as the response variables. The model identified by QIC for RPE contained 2 variables as follows: HSR per minute and distance in deceleration per minute, whereas sRPE was modeled with 3 predictors as follows: PlayerLoad, HSR, and distance in acceleration. The findings demonstrate that RPE does not reflect the intensity of a training session and that sRPE can be a useful, simple, and cost-effective tool for monitoring TL.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Profiling the Post-match Top-up Conditioning Practices of Professional
           Soccer Substitutes: An Analysis of Contextual Influences
    • Authors: Hills; Samuel P.; Barrett, Stephen; Busby, Matt; Kilduff, Liam P.; Barwood, Martin J.; Radcliffe, Jon N.; Cooke, Carlton B.; Russell, Mark
      Abstract: imageHills, SP, Barrett, S, Busby, M, Kilduff, LP, Barwood, MJ, Radcliffe, JN, Cooke, CB, and Russell, M. Profiling the post-match top-up conditioning practices of professional soccer substitutes: An analysis of contextual influences. J Strength Cond Res 34(10): 2805–2814, 2020—Soccer practitioners implement “top-up” conditioning sessions to compensate for substitutes' limited match-play exposure. Although perceived to be valuable for reducing injury risk and augmenting positive physical adaptations, little research has considered the demands of post-match top-up training. To quantify post-match top-up responses, 31 professional soccer players wore 10 Hz microelectromechanical systems after 37 matches whereby they were selected in the match-day squad as substitutes (184 observations; 6 ± 5 observations·player−1). Linear mixed models and effect sizes (ES) assessed the influence of contextual factors on 23 physical performance variables. Top-ups lasted 17.13 ± 7.44 minutes, eliciting total and high-speed distances of 1.7 ± 6.2 km and 0.4 ± 1.7 km, respectively. Each contextual factor (i.e., position, substitution timing, match location, result, time of day, stage of the season, and fixture density) influenced at least 4 of the dependent variables profiled (p ≤ 0.05). Top-up duration; total, moderate-speed, and low-speed distance; and the number of repeated high-intensity efforts were greater for unused vs. used substitutes (ES: 0.38–0.73, small to moderate). Relative to away matches, home top-ups elicited heightened total, low-speed, and high-speed distances, alongside more moderate-speed accelerations and decelerations, and repeated high-intensity efforts (ES: 0.25–0.89, small to moderate). Although absolute and relative running distances were generally the highest when the fixture density was low, the greatest acceleration and deceleration demands were observed during the most congested fixture periods. Late-season top-ups typically elicited lower absolute physical responses than early and mid-season sessions. These data provide important information for practitioners when considering the aims and design of substitute top-up conditioning sessions, particularly with reference to contextual influences.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Interlimb Asymmetries in Youth Tennis Players: Relationships With
    • Authors: Madruga-Parera; Marc; Bishop, Chris; Fort-Vanmeerhaeghe, Azahara; Beltran-Valls, Maria R.; Skok, Oliver G.; Romero-Rodríguez, Daniel
      Abstract: imageMadruga-Parera, M, Bishop, C, Fort-Vanmeerhaeghe, A, Beltran-Valls, MR, Gonzalo-Skok, O, and Romero-Rodríguez, D. Interlimb asymmetries in youth tennis players: relationships with performance. J Strength Cond Res 34(10): 2815–2823, 2020—Change of direction speed (CODS) has been highlighted as a critical component of tennis. Interlimb asymmetries have been commonly studied in jump tests, but less attention given to the topic during CODS. The aim of this study was to quantify interlimb asymmetries in jumping and CODS (during traditional and isoinertial tests) and establish their relationship with measures of physical performance. Twenty-two elite youth tennis players (16.3 ± 1.4 years) performed single-leg countermovement jump (SLCMJ), single-leg broad jump, and single-leg lateral jump, a double 180° turn CODS test, and shuffle lateral step and crossover step with an isoinertial resistance device. Paired-samples t-tests revealed significant differences between limbs for all tests (p < 0.05). Interlimb asymmetry scores ranged from 1.83 to 15.03%, and a 1-way repeated-measures analysis of variance showed significant differences between interlimb asymmetry scores across multiple tests (p < 0.05). Spearman's rank order r correlations showed significant negative relationships between CODS asymmetry and SLCMJ performance on both limbs (r = −0.50; p = 0.02 and r = −0.53; p = 0.01) and CODS performance on both limbs (r = 0.50; p = 0.02 and r = 0.63; p = 0.002). These results show the test-specific nature of asymmetries in youth tennis athletes, with the SLCMJ presenting the greatest magnitude of asymmetry. Furthermore, interlimb differences during CODS were associated with reduced performance during jumping and CODS tests, suggesting the monitoring of asymmetries within this population may therefore be warranted.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Relationships Between Highly Skilled Golfers' Clubhead Velocity and
           Vertical Ground Reaction Force Asymmetry During Vertical Jumps and an
           Isometric Midthigh Pull
    • Authors: Wells; Jack E.T.; Mitchell, Andrew C.S.; Charalambous, Laura H.; Fletcher, Iain M.
      Abstract: imageWells, JET, Mitchell, ACS, Charalambous, LH, and Fletcher, IM. Relationships between highly skilled golfers' clubhead velocity and vertical ground reaction force asymmetry during vertical jumps and an isometric midthigh pull. J Strength Cond Res 34(10): 2824–2831, 2020—Clubhead velocity (CHV) is a commonly measured variable within golf due to strong associations with increased drive distance. Previous research has revealed significant relationships between CHV and vertical ground reaction force (vGRF) variables during bilateral tasks including a countermovement jump (CMJ), squat jump (SJ), drop jump (DJ), and isometric midthigh pull (IMTP). Asymmetries have been linked to performance outcomes in a number of sports; however, few studies have assessed asymmetries within golf. The current study, therefore, examined the relationships between CHV and vGRF asymmetries for CMJ positive impulse, SJ positive impulse, DJ positive impulse, and IMTP peak force (PF). Furthermore, the level of agreement for asymmetries between protocols was assessed by using Kappa coefficients. Fifty highly skilled (handicap ≤5) male golfers attended laboratory and range-based testing sessions. Positive impulse and PF were measured using a dual force platform system, with CHV measured using a TrackMan 3e launch monitor. There was no significant relationship (r = −0.14 to 0.22) between CHV and each of the vGRF asymmetry measures. Of the golfers tested, 26 had a “real” asymmetry in the CMJ, 18 had a “real” asymmetry in the SJ, 25 had a “real” asymmetry in the DJ, and 27 had a “real” asymmetry in the IMTP. Kappa coefficients indicated that asymmetries rarely favored the same limb (k = 0.06 to 0.39) with asymmetries varying for individual golfers between protocols. As such, asymmetries are neither beneficial nor detrimental to CHV but are inherently individual and dependent on the task.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Activity Profile of Elite Netball Umpires During Match Play
    • Authors: Spencer; Kirsten; Paget, Natasha; Farley, Oliver R.L.; Kilding, Andrew E.
      Abstract: imageSpencer, KN, Paget, N, Farley, ORL, and Kilding, AE. Activity profile of elite netball umpires during match play. J Strength Cond Res 34(10): 2832–2839, 2020—The study aimed to determine activity profiles of officials in elite netball. Physical demands of Load·min−1 (au) representing accumulated accelerations by triaxial accelerometers during matches and exercise-to-rest ratio were measured using global positioning systems (Catapult, MinimaxX S4). Physiological demands were quantified by estimated equivalent distance and heart rate (HR) (MeanHR, percentage HRpeak, and HRzones) and movement variables (frequency, mean time, and percentage of total time) were coded using Sportscode Elite (Version 10, Hudl, Lincoln, Nebraska). Differences were analyzed by periods (Q1–Q4). Load·min−1 (au) (M = 407 ± 66) significantly varied with time (F [3, 55] = 3.42, p = 0.02) and the highest percentage of exercise-to-rest performed in Q1 (21 ± 5%). Estimated equivalent distance (3,839 ± 614 m) varied significantly with time (F [3, 56] = 3.18, p = 0.03), the umpires spent longest duration of time (35%) in HRzone 3 (75–85% of HRpeak). Mean HR significantly decreased with time (p < 0.01; Q1 [157 ± 13], quarter 2 [156 ± 12], and Q4 [153 ± 14]). Umpires spent 77% in rest-recovery ratio movements and 23% of time exercise-to-rest ratio. In summary, netball umpiring is characterized by intermittent, short, high-intensity activity (sprinting, sidestepping, and turn to change direction), with increasing periods of rest-recovery (walking and standing).
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Lumbopelvic-Hip Complex and Scapular Stabilizing Muscle Activations During
           Full-Body Exercises With and Without Resistance Bands
    • Authors: Wasserberger; Kyle W.; Downs, Jessica L.; Barfield, Jeff W.; Williams, Teasie K.; Oliver, Gretchen D.
      Abstract: imageWasserberger, KW, Downs, JL, Barfield, JW, Williams, TK, and Oliver, GD. Lumbopelvic-hip complex and scapular stabilizing muscle activations during full-body exercises with and without resistance bands. J Strength Cond Res 34(10): 2840–2848, 2020—Inefficient sequencing in the kinetic chain has been linked to decreased performance and increased injury risk. Resistance band usage is very common in baseball/softball due to accessibility and low cost. However, resistance band use has primarily focused on the rotator cuff and surrounding shoulder musculature, thereby ignoring the rest of the kinetic chain. Currently, it is unclear whether resistance bands are effective tools for training musculature outside the throwing extremity. Thus, the purpose of this study was to examine muscle activations of the lumbopelvic-hip complex (LPHC) and scapular stabilizing musculature during 4 full-body exercises with and without the use of a resistance band. Twenty healthy, active individuals (174.39 ± 1.58 cm; 74.10 ± 1.75 kg; 21.85 ± 1.13 years) participated. Data were collected through surface electromyography for the LPHC and scapular stabilizing musculature during 4 full-body exercises with and without a resistance band. Statistical analyses were used to determine significant differences in activation levels between exercises and within exercises between conditions. Data showed a significant difference on muscle activation based on the interaction between resistance band usage and exercise choice (Λ = 0.276, F24, 136.92 = 3.19, p < 0.001). Adding a resistance band was effective in increasing muscle activation within the scapular stabilizing musculature. Conversely, the use of a resistance band was not as effective in increasing the activation of LPHC musculature. Future studies should investigate exercises that increase LPHC musculature activation. Coaches and clinicians can use these results to make more informed decisions when prescribing exercises to athletes for performance enhancement and rehabilitation.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Normative Reference Values for High School-Aged American Football Players
    • Authors: McKay; Brianna D.; Miramonti, Amelia A.; Gillen, Zachary M.; Leutzinger, Todd J.; Mendez, Alegra I.; Jenkins, Nathaniel D.M.; Cramer, Joel T.
      Abstract: imageMcKay, BD, Miramonti, AA, Gillen, ZM, Leutzinger, TJ, Mendez, AI, Jenkins, NDM, and Cramer, JT. Normative reference values for high school-aged American football players. J Strength Cond Res 34(10): 2849–2856, 2020—The purpose of the present report was to provide test- and position-specific normative reference values for combine test results based on a large, nationally representative sample of high school-aged American football players in their freshman, sophomore, and junior classes. Cross-sectional anthropometric and performance data were obtained from 12 different high school American football recruiting combines between March 7, 2015, and January 9, 2016, across the United States. Subjects included a sample (n = 7,478) of high school-aged American football athletes in their junior (n = 3,779), sophomore (n = 2,514), and freshman (n = 1,185) classes. The database included combine date, school state, position, class, height, body mass (BM), 40-yard dash, pro-agility, 3-cone, vertical jump, broad jump, and power push-up. Each player self-classified their American football positions as defensive back, defensive end, defensive linemen, linebacker, offensive linemen, quarterback, running back, tight end (TE), or wide receiver. Test- and position-specific normative values were generated by aggregating data from freshman, sophomore, and junior classes. Mean differences were found among classes for all positions and all measurements (p ≤ 0.05), except for TE BM (p> 0.05). Greater differences for all variables were observed from freshman to sophomore classes than from sophomore to junior classes. These normative reference values may provide realistic comparisons and evaluations in performance for young American football players, parents, and coaches with collegiate football aspirations. High school strength and conditioning professionals should use these norms to set attainable goals and reward accomplishments for young football players.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Acute Effects of Battle Rope Exercise on Performance, Blood Lactate
           Levels, Perceived Exertion, and Muscle Soreness in Collegiate Basketball
    • Authors: Chen; Wei-Han; Yang, Wen-Wen; Lee, Yi-Hua; Wu, Huey-June; Huang, Chen-Fu; Liu, Chiang
      Abstract: imageChen, WH, Yang, WW, Lee, YH, Wu, HJ, Huang, CF, and Liu, C. Acute effects of battle rope exercise on performance, blood lactate levels, perceived exertion, and muscle soreness in collegiate basketball players. J Strength Cond Res 34(10): 2857–2866, 2020—This study investigated the acute effects of battle rope (BR) exercise on basketball players' performance, blood lactate levels, rating of perceived exertion (RPE), and perceived muscle soreness. Fifteen well-trained Division-I male basketball players underwent the same test procedure at baseline, before BR exercise (30 minutes of rest after the baseline test), and after BR exercise. The 30-minute experimental protocol comprised 6 BR exercises at a work-to-rest ratio of 1:2 (20-second exercise and 40-second rest). Shooting accuracy, basketball chest pass speed, countermovement jump (CMJ) height, blood lactate levels, RPE (Borg Category-Ratio-10 scale), and perceived muscle soreness (visual analog scale, 0–100 mm) were measured in each test. The results indicated no change for any variables between baseline and before BR exercise. After BR exercise, performance decrements (p < 0.05) were recorded in shooting accuracy (16.9%) and basketball chest pass speed (9.1%), but no significant changes were observed for CMJ height. Battle rope exercise caused increases in blood lactate levels (13.6 mmol·L−1), RPE (9.9), and perceived muscle soreness (upper-limb: 63–67 mm; trunk: 43–68 mm; and lower-limb: 45–52 mm). In conclusion, BR exercise is physically demanding on the upper body, resulting in decreased performance in shooting accuracy and basketball chest pass speed. Battle rope exercise may not be beneficial before a practice or game because it triggers acute exercise-induced performance decrements and fatigue. However, BR exercise may be suitable for basketball training sessions in which the objective is to strengthen technical skills under fatiguing conditions.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Time Course of Recovery From Resistance Exercise With Different Set
    • Authors: Pareja-Blanco; Fernando; Rodríguez-Rosell, David; Aagaard, Per; Sánchez-Medina, Luis; Ribas-Serna, Juan; Mora-Custodio, Ricardo; Otero-Esquina, Carlos; Yáñez-García, Juan Manuel; González-Badillo, Juan José
      Abstract: imagePareja-Blanco, F, Rodríguez-Rosell, D, Aagaard, P, Sánchez-Medina, L, Ribas-Serna, J, Mora-Custodio, R, Otero-Esquina, C, Yáñez-García, JM, and González-Badillo, JJ. Time course of recovery from resistance exercise with different set configurations. J Strength Cond Res 34(10): 2867–2876, 2020—This study analyzed the response to 10 resistance exercise protocols differing in the number of repetitions performed in each set (R) with respect to the maximum predicted number (P). Ten males performed 10 protocols (R(P): 6(12), 12(12), 5(10), 10(10), 4(8), 8(8), 3(6), 6(6), 2(4), and 4(4)). Three sets with 5-minute interset rests were performed in each protocol in bench press and squat. Mechanical muscle function (countermovement jump height and velocity against a 1 m·s−1 load, V1-load) and biochemical plasma profile (testosterone, cortisol, growth hormone, prolactin, IGF-1, and creatine kinase) were assessed at several time points from 24-hour pre-exercise to 48-hour post-exercise. Protocols to failure, especially those in which the number of repetitions performed was high, resulted in larger reductions in mechanical muscle function, which remained reduced up to 48-hour post-exercise. Protocols to failure also showed greater increments in plasma growth hormone, IGF-1, prolactin, and creatine kinase concentrations. In conclusion, resistance exercise to failure resulted in greater fatigue accumulation and slower rates of neuromuscular recovery, as well as higher hormonal responses and greater muscle damage, especially when the maximal number of repetitions in the set was high.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Explosive Push-ups: From Popular Simple Exercises to Valid Tests for
           Upper-Body Power
    • Authors: Zalleg; Dalenda; Ben Dhahbi, Anis; Dhahbi, Wissem; Sellami, Maha; Padulo, Johnny; Souaifi, Marouen; Bešlija, Tea; Chamari, Karim
      Abstract: imageZalleg, D, Ben Dhahbi, A, Dhahbi, W, Sellami, M, Padulo, J, Souaifi, M, Bešlija, T, and Chamari, K. Explosive push-ups: From popular simple exercises to valid tests for upper-body power. J Strength Cond Res 34(10): 2877–2885, 2020—The purpose of this study was to assess the logical and ecological validity of 5 explosive push-up variations as a means of upper-body power assessment, using the factorial characterization of ground reaction force-based (GRF-based) parameter outputs. Thirty-seven highly active commando soldiers (age: 23.3 ± 1.5 years; body mass: 78.7 ± 9.7 kg; body height: 179.7 ± 4.3 cm) performed 3 trials of 5 variations of the explosive push-up in a randomized-counterbalanced order: (a) standard countermovement push-up, (b) standard squat push-up, (c) kneeling countermovement push-up, (d) kneeling squat push-up, and (e) drop-fall push-up. Vertical GRF was measured during these exercises using a portable force plate. The initial force-supported, peak-GRF and rate of force development during takeoff, flight time, impact force, and rate of force development impact on landing were measured. A significant relationship between initial force-supported and peak-GRF takeoff was observed for the countermovement push-up (CMP) exercises (standard countermovement push-up, kneeling countermovement push-up, and drop-fall push-up) and squat push-up (SP) exercises (standard squat push-up and kneeling squat push-up) (r = 0.58 and r = 0.80, respectively; p < 0.01). Furthermore, initial force supported was also negatively correlated to a significant degree with flight time for both CMP and SP (r = −0.74 and r = −0.80; p < 0.01, respectively). Principal component analysis (PCA) showed that the abovementioned 6 GRF-based variables resulted in the extraction of 3 significant components, which explained 88.9% of the total variance for CMP, and 2 significant components, which explained 71.0% of the total variance for SP exercises. In summary, the PCA model demonstrated a great predictive power in accounting for GRF-based parameters of explosive push-up exercises, allowing for stronger logical and ecological validity as tests of upper-body power. Furthermore, it is possible to adjust the intensity level of the push-up exercise by altering the starting position (i.e., standard vs. kneeling).
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Immune Response Related With Skin Thermal Pattern in Judokas: A New
           Application for Infrared Thermography'
    • Authors: Brito; Ciro J.; Moreira, Danilo G.; Ferreira, José J.; Díaz-de-Durana, Alfonso L.; Miarka, Bianca; Marins, João C.B.; Sillero-Quintana, Manuel
      Abstract: imageBrito, CJ, Moreira, DG, Ferreira, JJ, Díaz-de-Durana, AL, Miarka, B, Bouzas Marins, JC, and Sillero-Quintana, M. Immune response related with skin thermal pattern in judokas: A new application for infrared thermography? J Strength Cond Res 34(10): 2886–2894, 2020—This study investigated the association between body skin temperature (BST) and immune response after judo training, and compared the immune responses considering 2 post-training skin thermal pattern (“spots”—SPT and “localized”—LOC). For this, we evaluated 32 (25-male) black-belt judokas from the Spanish Junior National Team (18.0 ± 3.5 years, 72.4 ± 18.4 kg, and 17.1 ± 7.5% body fat). White blood cell and BST measurements were performed at pre-training, immediately, 1, and 24-hour post-training. Body skin temperature (° C) was estimated by skin temperature from 4 regions of interest (chest, upper arm, thigh, and calf). The main results indicated that 13 judokas were classified as SPT and 19 as LOC. In comparison with LOC, SPT had a significantly lower BST post-training (SPT = 33.0 ± 0.4 vs. LOC = 33.6 ± 0.8° C; p = 0.016), lower blood concentration of leukocytes (SPT = 7.9 ± 1.9 vs. LOC = 8.9 ± 1.9 cells × 103 per mm3; p ≤ 0.001), and neutrophils (SPT = 5.5 ± 1.7 vs. LOC = 6.1 ± 2.2 cells × 103 per mm3; p ≤ 0.001). In conclusion, the BST and immune response after judo training seem to be not associated. However, when the skin thermal pattern is considered, the SPT skin thermal pattern presented a lower post-training BST, blood leukocytes, and neutrophils in comparison with the LOC group. These results show a possible relationship between skin thermal pattern and immune responses for the first time; however, further studies are needed to confirm the evidence presented here.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Effects of Eccentric Cycling Performed at Long vs. Short Muscle Lengths on
           Heart Rate, Rate Perceived Effort, and Muscle Damage Markers
    • Authors: Peñailillo; Luis; Aedo, Carolina; Cartagena, Mayari; Contreras, Alejandra; Reyes, Alvaro; Ramirez-Campillo, Rodrigo; Earp, Jacob E.; Zbinden-Foncea, Hermann
      Abstract: imagePeñailillo, L, Aedo, C, Cartagena, M, Contreras, A, Reyes, A, Ramirez-Campillo, R, Earp, JE, and Zbinden-Foncea, H. Effects of eccentric cycling performed at long vs. short muscle lengths on heart rate, rate perceived effort, and muscle damage markers. J Strength Cond Res 34(10): 2895–2902, 2020—It is possible that the magnitude of muscle damage in eccentric cycling is dependent on seat position that could affect the muscle length changes during eccentric contractions. However, no previous study has investigated the effect of seat position on muscle damage and metabolic demand in eccentric exercise. Thus, this study compared 2 seating positions; seat forward in which knee extensor muscles were stretched longer (LONG) and seat back in which the muscles were stretched shorter (SHORT). Young men performed 30 minutes of eccentric cycling at 80% of maximal concentric power output at either LONG (n = 10) or SHORT (n = 10) condition. Heart rate and rate perceived effort (RPE) during exercise, changes in maximal voluntary isometric contraction (MVC) strength of the knee extensors, muscle soreness assessed by a visual analog scale (VAS), and pressure-pain threshold (PPT) before, immediately after, and 24–72 hours after exercise were compared between conditions. Heart rate and RPE were significantly greater in LONG than SHORT group (9.5 and 19.0%, respectively). Post-exercise reduction in MVC was 8.4–14.0% greater in LONG than SHORT group from immediately after to 48 hours after exercise. In addition, VAS was greater in LONG than SHORT group from 48 to 72 hours after exercise, and vastus medialis PPT was greater in SHORT than LONG group from 24 to 72 hours after exercise (p < 0.05). These results suggest that muscle damage and metabolic demand are greater when seat is set back than forward. Thus, when prescribing eccentric cycling to individuals who are unaccustomed to eccentric cycling, it is better to set the seat far from the pedals.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Effects of Lower-Body Muscular Fatigue on Vertical Jump and Balance
    • Authors: Cooper; Christina N.; Dabbs, Nicole C.; Davis, Judith; Sauls, Nicole M.
      Abstract: imageCooper, CN, Dabbs, NC, Davis, J, and Sauls, NM. Effects of lower-body muscular fatigue on vertical jump and balance performance. J Strength Cond Res 34(10): 2903–2910, 2020—Lower-body fatigue can lead to a decline in vertical jump (VJ) and balance performance due to decreased motor control and coordination. The purpose is to determine the effects of lower-body fatigue on VJ and balance performance. Twenty-four recreationally trained individuals participated in a single 1-hour familiarization and testing session. Participants were familiarized with balance, countermovement vertical jump (CMVJ), and static vertical jump (SVJ) using the Vertec. Three trials of static and dynamic balance tests were completed. Three trials of a SVJ and CMVJ were completed in a randomized order pre/post fatigue protocol. Three trials of double-leg and single-leg tests were performed. Dependent t tests analyzed differences between pre/post fatigue protocol for jumping and balance measures. There was a significant (p < 0.001) difference between pre/post measures for SVJ-H (height), CMVJ-H, and CMVJ peak power (PP). Results showed an interaction (p < 0.05) for group by time for CMVJ-H, CMVJ-peak force (PF), SVJ-PF, and SVJ-PP. There were no main effects (p> 0.05) for time or group for SVJ-rate of velocity development and SVJ-impact force (IF). There were no interactions, time effects, and group effects for balance variables (p> 0.05). Bosco protocol decreased VJ height and PF in SVJ, and VJ height and PF, IF, peak velocity, and PP for CMVJ potentially due to decreased muscle control, coordination, and force-generating capacity after fatigue. Practitioners should consider fatiguing effects on individuals performing jumping motions but it seems that fatigue has no effect on balance.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Knowledge, Attitudes, and Beliefs of Youth Sports Coaches Regarding Sport
           Volume Recommendations and Sport Specialization
    • Authors: Post; Eric G.; Trigsted, Stephanie M.; Schaefer, Daniel A.; Cadmus-Bertram, Lisa A.; Watson, Andrew M.; McGuine, Timothy A.; Brooks, Margaret Alison; Bell, David R.
      Abstract: imagePost, EG, Trigsted, SM, Schaefer, DA, Cadmus-Bertram, LA, Watson, AM, McGuine, TA, Brooks, MA, and Bell, DR. Knowledge, attitudes, and beliefs of youth sports coaches regarding sport volume recommendations and sport specialization. J Strength Cond Res 34(10): 2911–2919, 2020—Overuse injuries in youth athletes are becoming increasingly common, which may be a result of the prevalence of year-round specialized sport participation. Previous research has identified sport volume recommendations related to months per year, hours per week, and simultaneous participation in multiple sports leagues. Coaches are a primary influence on a youth athlete's decision to specialize in a single sport. Therefore, identifying coaches' baseline beliefs and perceptions is important for developing strategies to educate coaches about safe sport participation. A total of 253 youth sport coaches (207 males) completed an anonymous online questionnaire regarding knowledge of sport volume recommendations and attitudes and beliefs regarding sport specialization. Eligible participants were required to serve as a head or assistant coach of a youth sport team in the past 12 months whose members were between the ages of 12 and 18 years. Most coaches were unaware of recommendations regarding the maximum number of months per year (79.4%), hours per week in 1 sport (79.3%), or number of simultaneous leagues for an athlete to participate in to reduce injury (77.6%). Fewer than half (43.2%) of all coaches were “very” or “extremely” concerned about the risk of injury in youth sports. A majority (60.1%) believed that sport specialization was either “quite a bit” or “a great deal” of a problem. Two-thirds (67.2%) responded that year-round participation in a single sport was either “very” or “extremely” likely to increase an athlete's risk of injury. Although the responses to this survey were predominantly from coaches from 1 state, our results suggest that coaches are unaware of sport volume recommendations but are concerned about specialization. Future efforts are needed to communicate these recommendations to coaches to reduce the risk of overuse injury in youth sports.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Monitoring the External and Internal Load Under 2 Teaching Methodologies
    • Authors: González-Espinosa; Sergio; Antúnez, Antonio; Feu, Sebastián; Ibáñez, Sergio J.
      Abstract: imageGonzález-Espinosa, S, Antúnez, A, Feu, S, and Ibáñez, SJ. Monitoring the external and internal load under 2 teaching methodologies. J Strength Cond Res 34(10): 2920–2928, 2020—The purpose of this study was to analyze and compare the physical demands produced by the implementation of 2 sport teaching methods during a class and their relation with the learning achieved by the students. Two intervention programs were used to teach the sport of basketball, one based on the direct instruction (DI) method and the other on the tactical-game approach (TGA). The intervention programs were administered to 4 groups of students, 2 for each methodology, with 88 students participating in the study. A total of 10 practical sessions were given, as well as a pre-test and post-test. The practical sessions and the tests were recorded with an inertial system for monitoring and recording physical activity and movement in real time. Differences were found between the methodologies in the teaching sessions in the variables m·min−1, acc·min−1, PL·min−1, and HRmax (p < 0.000). In the assessment tests, there were also differences between both methodologies in the walk and sprint variables (p < 0.005). The results obtained from the analysis of the sessions using each methodology show that the TGA method obtained better results in the variables of external and internal loads than the DI methodology. The TGA methodology permitted a greater development of the students' physical fitness. Moreover, performance in play was not associated with the achievement of higher values in the results of external and internal load in the tests. The students trained with the TGA methodology recorded better performance indicators in the game. These results lead us to recommend physical education teachers to use a student-centered approach in their lessons because it improved both the students' physical fitness and their sports performance.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Monitoring Training Load and Perceived Recovery in Female Basketball:
           Implications for Training Design
    • Authors: Sansone; Pierpaolo; Tschan, Harald; Foster, Carl; Tessitore, Antonio
      Abstract: imageSansone, P, Tschan, H, Foster, C, and Tessitore, A. Monitoring training load and perceived recovery in female basketball: Implications for training design. J Strength Cond Res 34(10): 2929–2936, 2020—This study investigated the relationship between internal training load and perceived recovery of semi-professional female basketball players during the competitive season. Eleven female players were monitored for 14 weeks during the in-season phase. For each event (training and game), data were collected as follows: (a) Total Quality Recovery (TQR) score before the event (TQRpre); (b) session Rating of Perceived Exertion (sRPE) 20 minutes after completion of the event, to calculate training load (s-TL) of the event; and (c) TQR scores 12 (TQRpost12) and 24 hours (TQRpost24) after the event. Data were analyzed for daily, weekly, and mesocycle (regular season; regional play-off; and national play-off) time frames. Daily analysis showed that: TQRpost12 was lower than TQRpre (p < 0.001) and TQRpost24 (p < 0.001); s-TL had a moderate negative correlation with TQRpost12 (r = −0.48, p = 0.002); the difference between TQRpre and RPE (TS-Δ) had a very large positive correlation with TQRpost12 (r = 0.70, p < 0.001); and TQRpost24 was not significantly correlated with training parameters. Weekly analysis highlighted a very large negative correlation between the acute:chronic workload ratio and TQR collected at the start of the following week (TQRfw) (r = −0.86, p < 0.001). Finally, although weekly TL and TQRfw did not differ between mesocycles, their correlation increased in the later seasonal phases. This study demonstrated negative relationships between training load and recovery of semi-professional female basketball players at daily, weekly, and mesocycle levels. Therefore, concurrently monitoring training and recovery with the sRPE method and TQR scale is recommended for designing training schedules in basketball.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Strength Determinants of Jump Height in the Jump Throw Movement in Women
           Handball Players
    • Authors: McGhie; David; Østerås, Sindre; Ettema, Gertjan; Paulsen, Gøran; Sandbakk, Øyvind
      Abstract: imageMcGhie, D, Østerås, S, Ettema, G, Paulsen, G, and Sandbakk, Ø. Strength determinants of jump height in the jump throw movement in women handball players. J Strength Cond Res 34(10): 2937–2946, 2020—The purpose of the study was to improve the understanding of the strength demands of a handball-specific jump through examining the associations between jump height in a jump throw jump (JTJ) and measures of lower-body maximum strength and impulse in handball players. For comparison, whether the associations between jump height and strength differed between the JTJ and the customarily used countermovement jump (CMJ) was also examined. Twenty women handball players from a Norwegian top division club participated in the study. Jump height was measured in the JTJ and in unilateral and bilateral CMJ. Lower-body strength (maximum isometric force, one-repetition maximum [1RM], impulse at ∼60% and ∼35% 1RM) was measured in seated leg press. The associations between jump height and strength were assessed with correlation analyses and t-tests of dependent r's were performed to determine if correlations differed between jump tests. Only impulse at ∼35% 1RM correlated significantly with JTJ height (p < 0.05), whereas all strength measures correlated significantly with CMJ heights (p < 0.001). The associations between jump height and strength were significantly weaker in the JTJ than in both CMJ tests for all strength measures (p = 0.001–0.044) except one. Maximum strength and impulse at ∼60% 1RM did not seem to sufficiently capture the capabilities associated with JTJ height, highlighting the importance of employing tests targeting performance-relevant neuromuscular characteristics when assessing jump-related strength in handball players. Further, CMJ height seemed to represent a wider range of strength capabilities and care should be taken when using it as a proxy for handball-specific movements.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Isometric Midthigh Pull Characteristics in Elite Youth Male Soccer
           Players: Comparisons by Age and Maturity Offset
    • Authors: Morris; Rhys O.; Jones, Ben; Myers, Tony; Lake, Jason; Emmonds, Stacey; Clarke, Neil D.; Singleton, Dave; Ellis, Matthew; Till, Kevin
      Abstract: imageMorris, RO, Jones, B, Myers, T, Lake, J, Emmonds, S, Clarke, ND, Singleton, D, Ellis, M, and Till, K. Isometric midthigh pull characteristics in elite youth male soccer players: Comparisons by age and maturity offset. J Strength Cond Res 34(10): 2947–2955, 2020—The purpose of this study was to (a) provide comparative isometric midthigh pull (IMTP) force-time characteristics for elite youth soccer players and (b) determine the effect of age and maturation on IMTP force-time characteristics. Elite male youth soccer players (U12 n = 51; U13 n = 54; U14 n = 56; U15 n = 45; U16 n = 39; and U18 n = 48) across 3 maturity offset groups (Pre n = 117; circa n = 84; and Post–peak height velocity n = 92) performed 2 maximal IMTP trials on a portable force platform (1,000 Hz). Absolute and relative values for peak force (PF) and impulse over 100 and 300 ms were analyzed. A full Bayesian regression model was used to provide probable differences similar to that of a frequentist p value. Advanced age and maturation resulted in superior IMTP force-time characteristics. Peak force demonstrated high probabilities of a difference between all consecutive age groups (p> 0.95). For absolute and relative impulse (100 and 300 ms), only 2 consecutive age groups (U14–15's and U16–18's) demonstrated high probabilities of a difference (p> 0.95) with large effects (d = 0.59–0.93). There were high probable differences between all maturity offset groups for PF and impulse with medium to large effects (d = 0.56–3.80). These were also reduced when expressed relative to body mass (relative PF and relative impulse). This study provides comparative IMTP force-time characteristics of elite male youth soccer players. Practitioners should consider individual maturation status when comparing players given the impact this has on force expression.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Training and Competition Activity Profiles of Australian Football Field
    • Authors: Jessiman; Sean W.; Harvey, Briana; Corrigan, Sean L.; Gastin, Paul B.
      Abstract: imageJessiman, SW, Harvey, B, Corrigan, SL, and Gastin, PB. Training and competition activity profiles of Australian football field umpires. J Strength Cond Res 34(10): 2956–2964, 2020—The purpose of this study was to determine the activity profiles of Australian football (AF) field umpires during training and competition, and subsequently assess the specificity to competition of locomotor training sessions. Microtechnology incorporating a 5-Hz (interpolated to 15 Hz) global positioning system sensor tracked the movements of 24 field umpires during matches at the Melbourne Cricket Ground and fitness and skill-based training sessions before competition. Paired t-tests or Wilcoxon signed-rank tests determined whether significant differences existed between single training session and competition paired samples, with Cohen's d effect size and percent differences describing the magnitude of the training-competition differences. Absolute measures of total (d = 5.4; percent difference = 85.8%) and high-speed distance (>14.4 km·h−1) (1.0; 36.9%), as well as accelerations (3.3; 106.3%) and decelerations (3.2; 107.5%) were significantly greater during competition compared with training (p < 0.001). When standardized for time, high-speed distance (1.4; 52.0%), sprint distance (>23.0 km·h−1) (0.9; 121.5%), sprint efforts (1.0; 107.4%), and high acceleration (1.1; 114.3%) and deceleration (0.6; 66.7%) events (≥3 m·s−2) were greater during training (p < 0.001). No difference between training and competition was observed for relative distance. A single training session did not match the volume of work during competition, due primarily to large differences in duration. By contrast, training sessions were higher in intensity, likely to compensate for the shorter duration of training. Further research is required to determine whether the total weekly training load is sufficient to maintain and develop the competition-specific fitness of AF field umpires.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Changes in Parameters of Oxidative Stress, Immunity, and Behavior in
           Endurance Athletes During a Preparation Period in Winter
    • Authors: Michalickova; Danica; Minic, Rajna; Kotur-Stevuljevic, Jelena; Andjelkovic, Marija; Dikic, Nenad; Kostic-Vucicevic, Marija; Slanar, Ondrej; Djordjevic, Brizita
      Abstract: imageMichalickova, D, Minic, R, Kotur-Stevuljevic, J, Andjelkovic, M, Dikic, N, Kostic-Vucicevic, M, Slanar, O, and Djordjevic, B. Changes in parameters of oxidative stress, immunity, and behavior in endurance athletes during a preparation period in winter. J Strength Cond Res 34(10): 2965–2973, 2020—The current study monitored markers of immunological and oxidative status in 9 male elite endurance athletes: V̇o2max: 68 ± 11 ml·kg−1·min−1, age: 24 ± 2.5 years, and training loads: 128 ± 21 metabolic equivalents-h·wk−1 during a 3-month preparation period in winter (January–March). Self-rated state of moods evaluation (by Profile of Mood States questionnaire) was performed, and blood samples were collected at the beginning and end of the study. Spectrophotometric methods and enzyme-linked immunosorbent assay were used for parameters' determination. The level of concanavalin A (ConA)-stimulated interferon-γ (IFN-γ) from peripheral blood mononuclear cells (PBMCs) was increased (562 [147–852] vs. 1,097 [451–1842] pg·ml−1, p = 0.013). Also, the level of transforming growth factor-1 (TGF-β1) in serum was elevated (2.5 [1.4–5.1] vs. 7.2 [4.9–8.2] ng·ml−1, p = 0.015). There was no change in the level of peptidoglycan (PGN)-stimulated interleukin (IL)-10 from PBMCs. There were no significant changes in PBMCs proliferation/viability on stimulation with ConA and PGN during the study. No changes in superoxide dismutase, prooxidative-antioxidative balance, total oxidant status (TOS), and thiobarbituric acid reactive substances were observed along the study. Total antioxidant status (TAS) was increased (910 ± 174 vs. 1,090 ± 102 μmol·L−1, p = 0.018), and activity of paraoxonase (PON1) was decreased (523 ± 295 vs. 335 ± 183 U·L−1, p = 0.003) at the end of the study. Advanced oxidation protein products were increased (25 ± 7.9 vs. 42 ± 7.6 μmol·L−1, p = 0.011). The self-rated sense of vigor significantly declined (20 ± 2.1 vs. 14 ± 3.4, p = 0.045). In conclusion, 3 months of regular training in winter induced prominent changes in cytokines, biomarkers of oxidative stress, and antioxidative enzyme activity. These changes might increase susceptibility of athletes to disease and muscle damage and consequently lead to performance reduction.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Heart Rate Variability Changes From Traditional vs. Ultra–Short-Term
           Recordings in Relation to Preseason Training Load and Performance in
           Futsal Players
    • Authors: Nakamura; Fábio Y.; Antunes, Pedro; Nunes, Célia; Costa, Júlio A.; Esco, Michael R.; Travassos, Bruno
      Abstract: imageNakamura, FY, Antunes, P, Nunes, C, Costa, JA, Esco, MR, and Travassos, B. Heart rate variability changes from traditional vs. ultra–short-term recordings in relation to preseason training load and performance in futsal players. J Strength Cond Res 34(10): 2974–2981, 2020—The aims of this study were to analyze heart rate variability (HRV) changes in futsal players during preseason training using both “criterion” (10-minute) and ultra-shortened (2-minute) measures, and to determine whether they were related to changes in the Yo-Yo Intermittent Recovery Test, level 1 (Yo-Yo IR1) performance and accumulated training load (TL). Eleven male competitive futsal players (age = 25.19 ± 4.70 years; body mass = 73.15 ± 11.70 kg; and height = 176.90 ± 5.01 cm) volunteered for the study. Data collection took place during the first to the fourth weeks of preseason training. Training load was monitored with session ratings of perceived exertion. The total distance (TD) covered during the Yo-Yo IR1 was recorded during week 1 and week 4. Heart rate variability was measured through the log-transformed root mean square of successive normal-to-normal interval differences using the ultra-short analysis, with its weekly mean (lnRMSSDM) and coefficient of variation (lnRMSSDCV) recorded, and by means of the criterion method (weeks 1 and 4). lnRMSSDM was likely higher at week 4 compared with week 1 using both criterion and ultra-short recordings. Moderate-to-large correlations were found between changes in the lnRMSSDM and lnRMSSDCV values and changes in TL and TD (r values ranged from −0.48 to 0.65). Changes in ultra-short HRV measures (i.e., increase in lnRMSSDM and decrease in lnRMSSDCV) during futsal preseason were associated with increased performance. The players who accumulated higher perceived TLs displayed smaller improvements in the Yo-Yo IR1 performance and HRV.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Upper-Body Strength Measures and Pop-Up Performance of Stronger and Weaker
    • Authors: Parsonage; Joanna; Secomb, Josh L.; Sheppard, Jeremy M.; Ferrier, Brendon K.; Dowse, Rebecca A.; Nimphius, Sophia
      Abstract: imageParsonage, J, Secomb, JL, Sheppard, JM, Ferrier, BK, Dowse, RA, and Nimphius, S. Upper-body strength measures and pop-up performance of stronger and weaker surfers. J Strength Cond Res 34(10): 2982–2989, 2020—The primary purpose of this study was to investigate the reliability of the isometric push-up (IPU), dynamic push-up (DPU), and force plate pop-up (FP POP) as measures of upper-body isometric and dynamic strength qualities in surfing athletes. Furthermore, the study aimed to compare pop-up performance between stronger and weaker surfers. Eighteen female (n = 9) and male (n = 9) surfers (age = 28.1 ± 6.4 years, mass = 69.6 ± 10.4 kg, and height = 172.5 ± 6.7 cm) completed a battery of upper-body strength assessments, of which exhibited high between-day reliability: IPU, (coefficient of variation [CV%] = 4.7, intraclass correlation coefficient [ICC] = 0.96), DPU (CV% = 5.0, ICC = 0.90), and FP POP (CV% = 4.4, ICC = 0.90). Participants were subsequently split into stronger (n = 9) and weaker (n = 9) surfers based on normalized peak force (PF) attained in the IPU. Pop-up performance was measured both in the water and during the FP POP and was referred to as time to pop-up (TTP). Significant between-group differences were observed for normalized PF during IPU (d = 1.59, p < 0.01) and DPU (d = 0.94 p = 0.04). Although not significant, there was a large magnitude difference in FP POP (d = 0.80, p = 0.08) and FP TTP (d = 0.85, p = 0.07). Significant correlations were identified between normalized IPU PF and normalized DPU FP (r = 0.69, p = 0.03) and FP TTP (r = 0.73, p = 0.02) in the stronger group. The weaker group exhibited a significant inverse correlation between normalized IPU PF and in-water TTP (r = −0.77, p < 0.01). The results suggest improvements in pop-up performance may be elicited by improving dynamic strength for stronger surfers, whereas pop-up performance in weaker surfers may be elicited by improving maximum strength. The upper-body strength assessments provided a novel insight into strength qualities that are associated with in-water performance of surfers (TTP).
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Effects of Different Weekly Sets-Equated Resistance Training Frequencies
           on Muscular Strength, Muscle Mass, and Body Fat in Older Women
    • Authors: Pina; Fábio L.C.; Nunes, João Pedro; Schoenfeld, Brad J.; Nascimento, Matheus A.; Gerage, Aline M.; Januário, Renata S. B.; Carneiro, Nelson H.; Cyrino, Edilson S.; Oliveira, Arli R.
      Abstract: imagePina, FLC, Nunes, JP, Schoenfeld, BJ, Nascimento, MA, Gerage, AM, Januário, RSB, Carneiro, NH, Cyrino, ES, and Oliveira, AR. Effects of different weekly sets-equated resistance training frequencies on muscular strength, muscle mass and body fat in older women. J Strength Cond Res 34(10): 2990–2995, 2020—The aim of this study was to analyze the effects of different resistance training (RT) frequencies (2 vs. 3 times per week) with an equivalent number of weekly sets performed between conditions on muscular strength and body composition in older women. Forty-seven older women (65 ± 4 years) were divided into 2 groups that performed a 12-week RT program either 2 (G2x and 3 sets) or 3 (G3x and 2 sets) times per week. The groups were evaluated before and after study on measures of body composition through dual-energy x-ray absorptiometry, and muscular strength through one repetition maximum (1RM) testing. Lean soft tissue was significantly increased in both groups (G2x = +1.7%, G3x = +1.7%), while only G3x reduced body fat after the intervention period (G2x = −0.7%, G3x = −2.9%). Similarly, significant increases were noted between conditions for 1RM scores in bench press (G2x = +11.8%, G3x = +11.9%) and knee extension (G2x = +17.4%, G3x = +10.8%). The results indicate that performing 2 or 3 RT sessions per week promotes similar improvements in muscular outcomes, while training more frequently may reduce body fat after 12 weeks of weekly sets-equated RT in untrained older women.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Resistance Training Improves a Cellular Health Parameter in Obese Older
           Women: A Randomized Controlled Trial
    • Authors: Ribeiro; Alex S.; Schoenfeld, Brad J.; Dos Santos, Leandro; Nunes, João Pedro; Tomeleri, Crisieli M.; Cunha, Paolo M.; Sardinha, Luis B.; Cyrino, Edilson S.
      Abstract: imageRibeiro, AS, Schoenfeld, BJ, dos Santos, L, Nunes, JP, Tomeleri, CM, Cunha, PM, Sardinha, LB, and Cyrino, ES. Resistance training improves a cellular health parameter in obese older women: a randomized controlled trial. J Strength Cond Res 34(10): 2996–3002, 2020—Phase angle (PhA) is a viable indicator of cellular health, with higher values reflecting better cellularity, cell membrane integrity, and cell function. Adaptive responses to resistance training (RT) on PhA may be important in obese older people. The main purpose of the present study was to investigate the effects of 8 weeks of RT on PhA in obese older women. Thirty-three obese older women (68.1 ± 5.7 years, 71.6 ± 10.1 kg, 154.5 ± 6.7 cm, 30.0 ± 4.1 kg·m−2, and 45.0 ± 6.0% body fat) were randomly allocated into 1 of 2 groups: a training group that performed the RT program (TG, n = 18) or a nonexercise control group (CG, n = 15). The whole-body RT consisted of an 8-week RT program involving 8 exercises performed for 3 sets of 8–12 repetitions 3 times a week. Anthropometric, body fat and fat-free mass, PhA, total body water (TBW), intracellular water (ICW), and extracellular water compartments were performed at before and after training. After the intervention period, the TG presented greater increases (p < 0.05) than CG for fat-free mass (TG = +1.3% and CG = −0.3%), TBW (TG = +2.0% and CG = −1.7%), ICW (TG = +3.1% and CG = −1.9%), and PhA (TG = +3.4% and CG = −1.4%), and lower values for percentage of body fat (TG = −1.3% and CG = +0.9%) and bioimpedance resistance (TG = −4.6% and CG = +2.3%). Our results suggest that 8 weeks of RT improves PhA—a cellular health parameter—in obese older women.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Essential Skills for Superior Wave-Riding Performance: A Systematic Review
    • Authors: Forsyth; James R.; Riddiford-Harland, Diane L.; Whitting, John W.; Sheppard, Jeremy M.; Steele, Julie R.
      Abstract: imageForsyth, JR, Riddiford-Harland, DL, Whitting, JW, Sheppard, JM, and Steele, JR. Essential skills for superior wave-riding performance: A systematic review. J Strength Cond Res 34(10): 3003–3011, 2020—To successfully and safely perform surfing maneuvers, surfers and their coaches need to know how to perform each maneuver correctly. Although some components of the sport are well understood, evidence-based recommendations in the scientific literature on how to perform surfing skills are sparse. The aim of this article was to systematically review the body of literature pertaining to discrete wave-riding skills and characteristics that are associated with the ability of surfers to successfully perform them. Searches of PubMed, SCOPUS, SPORTDiscus with Full-text, and Web of Science were undertaken in January 2019, to identify the most appropriate literature, with secondary searches of reference lists used to create a greater pool of possible articles. The review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA-P). Ten studies deemed appropriate for review captured data from 299 surfers, who were predominantly competitive (78.3%) and male (58.2%). The average Down and Black Quality Index of the articles was 76.3 ± 8.4%, with these articles focusing on the “pop-up” and landing skills. Performance indicators, such as isometric push-up peak forces, force-plate derived and in-water time to pop-up, relative peak forces generated when landing and time-to-stabilization, were all shown to be related to the physical characteristics of surfers and could affect the ability of surfers to successfully ride a wave. Findings from the studies included in this review suggest that the pop-up and landing exhibit trainable qualities that coaches and athletes can use to improve surfing performance.
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Erratum
    • Authors: da Silva Novaes; Jefferson; da Silva Telles, Luiz Guilherme; Monteiro, Est ˆeva˜ o Rios; da Silva Araujo, Gleisson; Vingren, Jakob L.; Panza, Patr´icia Silva; Reis, Victor Machado; Laterza, Mateus Camaroti; Vianna, Jeferson Macedo
      Abstract: No abstract available
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
  • Effects of Physical Exercise on the Expression of Micrornas: A Systematic
           Review: Corrigendum
    • Abstract: No abstract available
      PubDate: Thu, 01 Oct 2020 00:00:00 GMT-
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