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Manuel Mateo-March, Pedro L. Valenzuela, Xabier Muriel, Alexis Gandia-Soriano, Mikel Zabala, Alejandro Lucia, Jesús G. Pallares, and David Barranco-Gil

Purpose: The present study aimed to determine the influence of fatigue on the record power profile of professional male cyclists. We also assessed whether fatigue could differently affect cyclists of 2 competition categories. Methods: We analyzed the record power profile in 112 professional cyclists (n = 46 and n = 66 in the ProTeam [PT] and WorldTour [WT] category, respectively; age 29 [6] y, 8 [5] y experience in the professional category) during 2013–2021 (8 [5] seasons/cyclist). We analyzed their mean maximal power (MMP) values for efforts lasting 10 seconds to 120 minutes with no fatigue (after 0 kJ·kg−1) and with increasing levels of fatigue (after 15, 25, 35, and 45 kJ·kg−1). Results: A significant (P < .001) and progressive deterioration of all MMP values was observed from the lowest levels of fatigue assessed (ie, −1.6% to −3.0% decline after 15 kJ·kg−1, and −6.0% to −9.7% after 45 kJ·kg−1). Compared with WT, PT cyclists showed a greater decay of MMP values under fatigue conditions (P < .001), and these differences increased with accumulating levels of fatigue (decay of −1.8 to −2.9% [WT] with reference to 0 kJ·kg−1 vs −1.1% to −4.4% [PT] after 15 kJ·kg−1 and of −4.7% to −8.8% [WT] vs −7.6% to −11.6% [PT] after 45 kJ·kg−1). No consistent differences were found between WT and PT cyclists in MMP values assessed in nonfatigue conditions (after 0 kJ·kg−1), but WT cyclists attained significantly higher MMP values with accumulating levels of fatigue, particularly for long-duration efforts (≥5 min). Conclusions: Our findings highlight the importance of considering fatigue when assessing the record power profile of endurance athletes and support the ability to attenuate fatigue-induced decline in MMP values as a determinant of endurance performance.

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Jeremy N. Cohen, Kyle M.A. Thompson, Veronica K. Jamnik, Norman Gledhill, and Jamie F. Burr

Purpose: Along with past performance, professional teams consider physical fitness and physiological potential in determining the value of prospective draft picks. The National Hockey League (NHL) Combine fitness results have been examined for their ability to predict draft order, but not bona fide hockey performance. Therefore, we sought to identify the relationships of combine fitness test results to short- and long-term NHL performance. Methods: During NHL Combine fitness testing (1994–2007), a standardized battery of tests was conducted. Player performance (1995–2020) was quantified using career cumulative points, time on ice, transitional period to playing in the NHL, and NHL career length. Forward and defensive positions were considered separately. Goalies were not considered. Stepwise linear regression analysis was used to identify fitness variables that predict NHL success. Results: Overall models ranged in their predictive ability from 2% to 16%. The transitional period was predicted by peak leg power and aerobic capacity (V˙O2max; forwards, R 2 = .03, and defense, R 2 = .06, both P < .01). Points and time on ice within seasons 1 to 3 were predicted by peak leg power and V˙O2max for forwards and defense (R 2 = .02–.09, P < .01). Among players accumulating 10 NHL seasons, cumulative points were inversely related to upper-body push-strength-related variables in forwards (R 2 = .11) and defense (R 2 = .16; both P < .01). Conclusions: The NHL Combine fitness testing offers meaningful data that can inform the likelihood of future success. Peak leg power and V˙O2max predict league entry and early career success. Counterintuitively, upper-body strength is inversely related to long-term performance, which may offer insight into recruitment strategies, player development, or differential team roles.

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Martin Buchheit and Sian V. Allen

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Takaya Yoshimoto, Yoshihiro Chiba, Hayato Ohnuma, Takuya Yanaka, and Norihide Sugisaki

Purpose: This study aimed to investigate the level of muscle activity during sprint running using T2-weighted magnetic resonance imaging. Methods: Fourteen male sprinters (age 21.2 [4.0] y; height 171.8 [4.2] cm, weight 65.5 [5.3] kg, 100-m personal record 11.01 [0.41] s; mean [SD]) performed 3 sets of three 60-m round-trip sprints. Before and after the round-trip sprints, 3 T magnetic resonance imaging scans were performed to obtain the T2 values of the 14 athletes’ lower-extremity muscles. Results: After the 60-m round-trip sprints, the T2 value of the gluteus maximus, long head of biceps femoris, semitendinosus, semimembranosus, adductor brevis, adductor longus, adductor magnus, and gracilis increased significantly. The rate of change in the T2 values before and after the 60-m round-trip sprints was notably higher in the semitendinosus and gluteus maximus than in the other muscles. Conclusions: These findings demonstrate the specific physiological metabolism of the lower-extremity muscles during fast sprinting. There are particularly high levels of muscle activity in the gluteus maximus and semitendinosus during sprint performance.

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Pedro Acosta-Manzano, Francisco M. Acosta, Marta Flor-Alemany, Blanca Gavilán-Carrera, Manuel Delgado-Fernández, Laura Baena-García, Víctor Segura-Jiménez, and Virginia A. Aparicio

Physical fitness (PF) is a cornerstone of metabolic health. However, its role in maternal–fetal metabolism during pregnancy is poorly understood. The present work investigates: (i) the association of PF with maternal and fetal cardiometabolic markers, and with clustered cardiometabolic risk during pregnancy, and (ii) whether being fit counteracts cardiometabolic abnormalities associated with overweight/obesity. Several PF components (flexibility, lower and upper body strength, and cardiorespiratory fitness [CRF]) were objectively assessed in 151 pregnant women at gestational weeks 16 and 33, and an overall PF cluster score calculated. At the same times, maternal glycemic and lipid markers, cortisol, and C-reactive protein were assessed with standard biochemical methods, along with blood pressure and a proxy for insulin resistance, and a cardiometabolic risk cluster score determined. These analytes were also measured in maternal and umbilical cord arterial and venous blood collected at delivery. PF was found to be associated with several maternal and a small number of fetal cardiometabolic markers (p < .05). Lower and upper body muscle strength, CRF, overall PF (week 16), and CRF changes (weeks 16–33) were inversely associated with clustered cardiometabolic risk (p < .05). Normal weight fit women had lower values for insulin level, insulin resistance, triglycerides, low-density lipoprotein cholesterol, C-reactive protein, and diastolic blood pressure than did overweight/obese unfit women at week 16 (p < .05). In conclusion, greater PF, especially muscle strength and CRF in early–middle pregnancy, appears to be associated with a better metabolic phenotype, and may protect against maternal cardiometabolic risk. “Keep yourself fit and normal weight before and during early pregnancy” should be a key public health message.

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Riley R. Stefan, Clayton L. Camic, Garrett F. Miles, Attila J. Kovacs, Andrew R. Jagim, and Christopher M. Hill

Purpose: To determine the relative contributions of handgrip and individual finger strength for the prediction of climbing performance in a bouldering competition. A secondary aim was to examine the influence of body size, bouldering experience, and training habits. Methods: Sixty-seven boulderers (mean [SD], age = 21.1 [4.0] y; body mass = 69.5 [9.8] kg) volunteered for this study. Data collection occurred immediately before an indoor bouldering competition and involved the assessment of handgrip and individual finger maximal force production using an electronic handheld dynamometer. The bouldering competition consisted of 70 routes graded V0 to V8, with higher point values awarded for completing more difficult routes. Stepwise multiple regression analysis was used to examine the relative contributions of handgrip and individual finger strengths, body mass, height, bouldering experience, and bouldering frequency to the prediction of performance scores in the competition. Results: Ring finger pinch strength, bouldering experience, and bouldering frequency significantly (P < .05) contributed to the model (R2 = .373), whereas body mass; height; full handgrip strength, as well as index, middle, and little finger pinch strengths did not. The β weights showed that ring finger pinch strength (β = .430) was the most significant contributor, followed by bouldering experience (β = .331) and bouldering frequency (β = .244). Conclusions: The current findings indicated that trainable factors contributed to the prediction of bouldering performance. These results suggest greater bouldering frequency and experience likely contribute to greater isolated individual finger strength, thereby optimizing preparation for the diverse handholds in competitive rock climbing.

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Herbert Wagner, Matthias Hinz, Patrick Fuchs, Jeffrey W. Bell, and Serge P. von Duvillard

Purpose: In elite team handball, talent identification and selection of the best young players is a fundamental process in several national federations and clubs; however, literature addressing the specific game-based performance in team handball is almost nonexistent. Consequently, the aim of the study was to assess and compare the team-handball-specific game-based performance of elite male team handball players of different ages. Methods: Twelve under-23, 10 under-19, 10 under-17, and 10 under-15 elite male players performed the team-handball game-based performance test. During testing, oxygen uptake, heart rate, sprinting time in defense, offense, fast breaks, and fast retreats, as well as ball velocity and jump height in the jump shot, were measured. Results: Significant differences (P < .05) between under-23, under-19, under-17, and under-15 players were found for absolute peak oxygen uptake, defense, offense and fast break time, ball velocity, and jump height in the game-based performance test, as well as in body weight and height. Conclusion: The results revealed that with increasing age, elite male team handball players are heavier and taller (body weight and height); faster (team-handball offense, defense, and fast break); jump higher and throw faster (in the team-handball jump shot); and perform better aerobically (absolute peak oxygen uptake). The better performance in the under-23 and under-19 players compared with male adult players competing in a lower National Federation league (not on top-elite level) demonstrates that highly specific game-based physical performance determines the potential for developing young male team handball players for competition at the top level.

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Emily M. Partridge, Julie Cooke, Andrew J. McKune, and David B. Pyne

Purpose: This study evaluated the effect of partial-body cryotherapy (PBC) exposure 1, 2, or 3 hours before maximal-effort jump performance, salivary enzyme concentration, perceived readiness, and well-being. Methods: Male team-sport players (N = 27; 24.2 [3.6] y; 91.5 [13.2] kg) were exposed to a blinded bout of PBC (−135°C [6°C]) and control (−59°C [17°C]) either 1, 2, or 3 hours prior to countermovement jumps. Passive saliva samples were collected to determine α-amylase concentration. Self-reported performance readiness and well-being questionnaires were completed using a 1–5 Likert scale. Results: Differences in the change in mean countermovement jump velocity and absolute power between PBC and control were unclear at 1 hour (+1.9% [5.3%], P = .149; +0.7% [10.6%], P = .919; mean difference [90% confidence limits]), 2 hours (+3.3% [2.7%], P = .196; +7.8% [7.4%], P = .169), and 3 hours postexposure (+3.1% [3.3%], P = .467; +0.7% [4.8%], P = .327). Salivary α-amylase concentration was elevated 15 minutes postexposure in the 1-hour (+61% [14%], P = .008) and 2-hour groups (+55% [12%], P = .013). The increase in self-reported performance readiness was higher after PBC (+2.4 [1.2] units, P = .046) in the 2-hour group and by 1.4 (1.1) units (P = .023) after 3 hours. Mental fatigue was favorably decreased 2 hours after PBC exposure (+0.5 [0.1], P = .041). Conclusions: An acute exposure of PBC elicits potentially favorable but unclear changes in countermovement jump performance. The PBC enhances salivary α-amylase concentration and perceived performance readiness, reduces mental fatigue, and could be useful in sport-specific training or competitions.

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Cedric Leduc, Dan Weaving, Cameron Owen, Mathieu Lacome, Carlos Ramirez-Lopez, Maj Skok, Jason C. Tee, and Ben Jones

Purpose: Sleep is recognized as an important recovery strategy, yet little is known regarding its impact on postmatch fatigue. The aims of this study were to (1) describe sleep and postmatch fatigue, (2) understand how sleep is affected by contextual and match factors, and (3) assess how changes in sleep can affect postmatch fatigue. Methods: Twenty-three male rugby union players were monitored across 1 season (N = 71 player–match observations). Actigraphy was used during preseason to establish baseline sleep quality and quantity. Sleep was then measured 1 and 2 days after each match day (MD + 1 and MD + 2). Global positioning systems, notational analysis, and rating of perceived exertion represented external and internal load from matches. Subjective wellness and a standardized run were used to characterize postmatch fatigue 2 days prior (baseline) and at MD + 1 and MD + 2. Linear mixed models established the magnitude of change (effect size [ES]) between baseline, MD + 1, and MD + 2 for sleep and postmatch fatigue. Stepwise forward selection analysis ascertained the effect of match load on sleep and the effect of sleep on postmatch fatigue. Each analysis was combined with magnitude-based decisions. Results: Sleep characteristics and neuromuscular and perceptual postmatch fatigue were negatively affected at MD + 1 and MD + 2 (ES = small to very large). Kickoff and travel time had the greatest effect on sleep (ES = small). Wellness and soreness were influenced by sleep (fall-asleep time and fragmentation index) and collisions, respectively (ES = small). Conclusion: Sleep quality and quantity were affected independently of the match load (ie, running activity) sustained, and changes in sleep marginally affected postmatch fatigue.

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Kirsty M. Reynolds, Tom Clifford, Stephen A. Mears, and Lewis J. James

This systematic review analyzed whether carbohydrate source (food vs. supplement) influenced performance and gastrointestinal (GI) symptoms during endurance exercise. Medline, SPORTDiscus, and citations were searched from inception to July 2021. Inclusion criteria were healthy, active males and females aged >18 years, investigating endurance performance, and GI symptoms after ingestion of carbohydrate from a food or supplement, <60 min before or during endurance exercise. The van Rosendale scale was used to determine risk of bias, with seven studies having low risk of bias. A total of 151 participants from 15 studies were included in the review. Three studies provided 0.6–1 g carbohydrate/kg body mass during 5–45 min precycling exercise (duration 60–70 min) while 12 studies provided 24–80 g/hr carbohydrate during exercise (60–330 min). Except one study that suggested a likely harmful effect (magnitude-based inferences) of a bar compared to a gel consumed during exercise on cycling performance, there were no differences in running (n = 1) or cycling (n = 13) performance/capacity between food and supplemental sources. Greater GI symptoms were reported with food compared with supplemental sources. Highly heterogenous study designs for carbohydrate dose and timing, as well as exercise protocol and duration, make it difficult to compare findings between studies. A further limitation results from only one study assessing running performance. Food choices of carbohydrate consumed immediately before and during endurance exercise result in similar exercise performance/capacity responses to supplemental carbohydrate sources, but may slightly increase GI symptoms in some athletes, particularly with exercise >2 hr.