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Rich D. Johnston

Purpose: To explore the relationship between technical errors during rugby league games, match success, and physical characteristics. Methods: A total of 27 semiprofessional rugby league players participated in this study (24.8 [2.5] y, 183.5 [5.3] cm, 97.1 [11.6] kg). Aerobic fitness, strength, and power were assessed prior to the start of the competitive season before technical performance was tracked during 22 competitive fixtures. Attacking errors were determined as any error that occurred in possession of the ball that resulted in a handover to the opposition. Defensive errors included line breaks, penalties, and missed or ineffective tackles. Match outcome, the zone on the field in which each error occurred, and the number of errors in an error chain (≤60 s between errors) were assessed. Results: During a loss, there were more defensive errors in the 0- to 40-m zone than when a match was won (effect size = 0.99 [0.04–1.94]). Error chains were a predictor of conceding a try (P = .0001, r 2 = .22), with the odds ratio increasing to 2.33 when there were 7 errors per chain. High lower-body strength was associated with fewer defensive errors for backs (Bayes factor = 3.67) and forwards (Bayes factor = 19.31); relative bench press was also important for backs (Bayes factor = 3.21). Conclusions: Fewer defensive errors occur in the 0- to 40-m zone during winning matches; lower-body strength is strongly associated with fewer defensive errors in rugby league players.

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Daniel G. Hursh, Marissa N. Baranauskas, Chad C. Wiggins, Shane Bielko, Timothy D. Mickleborough and Robert F. Chapman

Endurance exercise performance in hypoxia may be influenced by an ability to maintain high minute ventilation (V˙E) in defense of reduced arterial oxyhemoglobin saturation. Inspiratory muscle training (IMT) has been used as an effective intervention to attenuate the negative physiological consequences associated with an increased V˙E, resulting in improved submaximal-exercise performance in normoxia. However, the efficacy of IMT on hypoxic exercise performance remains unresolved. Purpose: To determine whether chronic IMT improves submaximal-exercise performance with acute hypoxic exposure. Methods: A total of 14 endurance-trained men completed a 20-km cycling time trial (TT) in normobaric hypoxia (fraction of inspired oxygen [FiO2] = 0.16) before and after either 6 wk of an IMT protocol consisting of inspiratory loads equivalent to 80% of sustained maximal inspiratory pressure (n = 9) or a SHAM protocol (30% of sustained maximal inspiratory pressure; n = 5). Results: In the IMT group, 20-km TT performance significantly improved by 1.45 (2.0%), P = .03, after the 6-wk intervention. The significantly faster TT times were accompanied by a higher average V˙E (pre vs post: 99.3 [14.5] vs 109.9 [18.0] L·min−1, P = .01) and absolute oxygen uptake (pre vs post: 3.39 [0.52] vs 3.60 [0.58] L·min−1, P = .010), with no change in ratings of perceived exertion or dyspnea (P > .06). There were no changes in TT performance in the SHAM group (P = .45). Conclusion: These data suggest that performing 6 wk of IMT may benefit hypoxic endurance exercise performance lasting 30–40 min.

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Fernando Naclerio, Eneko Larumbe-Zabala, Mar Larrosa, Aitor Centeno, Jonathan Esteve-Lanao and Diego Moreno-Pérez

The impact of animal protein blend supplements in endurance athletes is scarcely researched. The authors investigated the effect of ingesting an admixture providing orange juice and protein (PRO) from beef and whey versus carbohydrate alone on body composition and performance over a 10-week training period in male endurance athletes. Participants were randomly assigned to a protein (CHO + PRO, n = 15) or a nonprotein isoenergetic carbohydrate (CHO, n = 15) group. Twenty grams of supplement mixed with orange juice was ingested postworkout or before breakfast on nontraining days. Measurements were performed pre- and postintervention on body composition (by dual-energy X-ray absorptiometry), peak oxygen consumption (V˙O2peak), and maximal aerobic speed. Twenty-five participants (CHO + PRO, n = 12; CHO, n = 13) completed the study. Only the CHO + PRO group significantly (p < .05) reduced whole-body fat (mean ± SD) (−1.02 ± 0.6 kg), total trunk fat (−0.81 ± 0.9 kg), and increased total lower body lean mass (+0.52 ± 0.7 kg), showing close to statistically significant increases of whole-body lean mass (+0.57 ± 0.8 kg, p = .055). Both groups reduced (p < .05) visceral fat (CHO + PRO, −0.03 ± 0.1 kg; CHO, −0.03 ± 0.5 kg) and improved the speed at maximal aerobic speed (CHO + PRO, +0.56 ± 0.5 km/hr; CHO, +0.35 ± 0.5 km/hr). Although consuming animal protein blend mixed with orange juice over 10 weeks helped to reduce fat mass and to increase lean mass, no additional performance benefits in endurance runners were observed.

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Fernando Klitzke Borszcz, Artur Ferreira Tramontin and Vitor Pereira Costa

Purpose: Functional threshold power (FTP), determined as 95% of the average power during a 20-min time trial, is suggested as a practical test for the determination of the maximal lactate steady state (MLSS) in cycling. Therefore, the objective of the present study was to determine the validity of FTP in predicting MLSS. Methods: A total of 15 cyclists, 7 classified as trained and 8 as well trained (mean [SD] maximal oxygen uptake 62.3 [6.4] mL·kg−1·min−1, maximal aerobic power 329 [30] W), performed an incremental test to exhaustion, an FTP test, and several constant-load tests to determine the MLSS. The bias ± 95% limits of agreement (LoA), typical error of the estimate (TEE), and Pearson coefficient of correlation (r) were calculated to assess validity. Results: For the power-output measures, FTP presented a bias ± 95% LoA of 1.4% ± 9.2%, a moderate TEE (4.7%), and nearly perfect correlation (r = .91) with MLSS in all cyclists together. When divided by training level, the bias ± 95% LoA and TEE were higher in the trained group (1.4% ± 11.8% and 6.4%, respectively) than in the well-trained group (1.3% ± 7.4% and 3.0%, respectively). For the heart-rate measurement, FTP presented a bias ± 95% LoA of −1.4% ± 8.2%, TEE of 4.0%, and very large correlation (r = .80) with MLSS. Conclusion: Therefore, trained and well-trained cyclists can use FTP as a noninvasive and practical alternative to estimate MLSS.

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Aline C. Tritto, Salomão Bueno, Rosa M.P. Rodrigues, Bruno Gualano, Hamilton Roschel and Guilherme G. Artioli

This study evaluated the effects of β-hydroxy-β-methylbutyrate free acid (HMB-FA) and calcium salt (HMB-Ca) on strength, hypertrophy, and markers of muscle damage. In this randomized, double-blind, placebo-controlled study, 44 resistance-trained men (age: 26 ± 4 years; body mass: 84.9 ± 12.0 kg) consuming ≥1.7 g·kg−1·day−1 of protein received HMB-FA (3 g/day; n = 14), HMB-Ca (3 g/day; n = 15), or placebo (PL; cornstarch, 3 g/day; n = 15) for 12 weeks, while performing a periodized resistance training program. Before and after intervention, lean body mass (measured with dual X-ray absorptiometry), maximal dynamic strength (one-repetition maximum), knee extension maximal isometric strength (maximal voluntary isometric contraction [MVIC]), cross-sectional area (measured with ultrasound), and muscle soreness were assessed. MVIC was also measured 48 hr after the first and the last training sessions. All groups increased lean body mass (main time effect: p < .0001; HMB-FA: 1.8 ± 1.8 kg; HMB-Ca: 0.8 ± 1.4 kg; PL: 0.9 ± 1.4 kg), cross-sectional area (main time effect: p < .0001; HMB-FA: 6.6 ± 3.8%; HMB-Ca: 4.7 ± 4.4%; PL: 6.9 ± 3.8%), one-repetition maximum bench press (main time effect: p < .0001; HMB-FA: 14.8 ± 8.4 kg; HMB-Ca: 11.8 ± 7.4 kg; PL: 11.2 ± 6.6 kg), MVIC (main time effect: p < .0001; HMB-FA: 34.4 ± 39.3%; HMB-Ca: 32.3 ± 27.4%; PL: 17.7 ± 20.9%) after the intervention, but no differences between groups were shown. HMB-FA group showed greater leg press strength after the intervention than HMB-Ca and PL groups (Group × Time interaction: p < .05; HMB-FA: 47.7 ± 31.2 kg; HMB-Ca: 43.8 ± 31.7 kg; PL: 30.2 ± 20.9 kg). MVIC measured 48 hr after the first and the last sessions showed no attenuation of force decline with supplementation. Muscle soreness following the first and last sessions was not different between groups. The authors concluded that neither HMB-Ca nor HMB-FA improved hypertrophy or reduced muscle damage in resistance-trained men undergoing resistance training ingesting optimal amounts of protein. HMB-FA but not HMB-Ca resulted in a statistically significant yet minor improvement on leg press one-repetition maximum.

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Jan G. Bourgois, Gil Bourgois and Jan Boone

Training-intensity distribution (TID), or the intensity of training and its distribution over time, has been considered an important determinant of the outcome of a training program in elite endurance athletes. The polarized and pyramidal TID, both characterized by a high amount of low-intensity training (below the first lactate or ventilatory threshold), but with different contributions of threshold training (between the first and second lactate or ventilatory threshold) and high-intensity training (above the second lactate or ventilatory threshold), have been reported most frequently in elite endurance athletes. However, the choice between these 2 TIDs is not straightforward. This article describes the historical, evolutionary, and physiological perspectives of the success of the polarized and pyramidal TID and proposes determinants that should be taken into account when choosing the most appropriate TID.

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Tim Op De Beéck, Arne Jaspers, Michel S. Brink, Wouter G.P. Frencken, Filip Staes, Jesse J. Davis and Werner F. Helsen

Purpose: The influence of preceding load and future perceived wellness of professional soccer players is unexamined. This paper simultaneously evaluates the external load (EL) and internal load (IL) for different time frames in combination with presession wellness to predict future perceived wellness using machine learning techniques. Methods: Training and match data were collected from a professional soccer team. The EL was measured using global positioning system technology and accelerometry. The IL was obtained using the rating of perceived exertion multiplied by duration. Predictive models were constructed using gradient-boosted regression trees (GBRT) and one naive baseline method. The individual predictions of future wellness items (ie, fatigue, sleep quality, general muscle soreness, stress levels, and mood) were based on a set of EL and IL indicators in combination with presession wellness. The EL and IL were computed for acute and cumulative time frames. The GBRT model’s performance on predicting the reported future wellness was compared with the naive baseline’s performance by means of absolute prediction error and effect size. Results: The GBRT model outperformed the baseline for the wellness items such as fatigue, general muscle soreness, stress levels, and mood. In addition, only the combination of EL, IL, and presession perceived wellness resulted in nontrivial effects for predicting future wellness. Including the cumulative load did not improve the predictive performances. Conclusions: The findings may indicate the importance of including both acute load and presession perceived wellness in a broad monitoring approach in professional soccer.

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Ben-El Berkovich, Aliza H. Stark, Alon Eliakim, Dan Nemet and Tali Sinai

Fasting, skipping meals, and dehydration are common methods of rapid weight loss used prior to competition in weight category sports. This study examines coaches’ attitudes, perceptions, and practices regarding rapid weight loss among judo and taekwondo athletes. A convenience sample of experienced coaches and trainers (n = 68) completed structured questionnaires. Participants in this study were 33.8 ± 9.3 years old; 57 were males and 11 were females; and 59% were certified coaches, with 71% reporting over 20 years of involvement in sports and 68% having more than 10 years of teaching experience. The majority (90%) reported that they usually supervised athletes through the weight loss process. Interventions for weight loss began at 12.7 ± 1.9 years of age, with a recommended precompetition weight loss duration of 16.2 ± 8.2 days and an average reduction of 1.5 ± 0.7 kg. The majority of the responders (92%) recommended that their athletes practice gradual weight loss methods using a combination of dehydration or increased physical activity (80.3%), sweat suits (50.8%), restricted fluid intake (39.3%), training in heated rooms (27%), and sauna (26.2%). Recommendations of spitting (27.8%) or using laxatives, diuretics, diet pills, or vomiting (21.3%) were also reported. Coaches and trainers often encouraged athletes to cut weight before competition. The methods recommended are potentially harmful with severe health risks, including compromised nutritional status and diminished athletic performance. This is of particular concern in young athletes who are still growing and developing physically. Enhancing knowledge and awareness for coaches, athletes, and parents regarding potential dangers, along with improved nutrition education, is critical for reducing the magnitude and misuse of rapid weight loss methods.

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Farid Farhani, Hamid Rajabi, Raoof Negaresh, Ajmol Ali, Sadegh Amani Shalamzari and Julien S. Baker

Purpose: To examine the validity and reliability of a novel futsal special performance test (FSPT) as a measure of futsal performance and skills. Methods: Thirty-six futsal players with different levels of experience were recruited and divided into 2 groups (elite and nonelite). Players participated in 4 sessions (at least 7 d apart): (1) familiarization session, (2) anaerobic power (Wingate test), (3) FSPT trial 1, and (4) FSPT trial 2. The FSPT was carried out on a futsal court (wooden sprung floor) and skills such as dribbling, rotation, long and short passing, and shooting were examined. Content validity was assessed by 6 experienced futsal coaches and instructors. Results: There was a significant correlation between FSPT and various aspects of anaerobic power (r = .5–.91; P ≤ .001). Moreover, significant large correlations were observed between test and retest of FSPT (r = .77; 95% confidence interval [CI], .56–.98; P ≤ .001). All instructors and coaches confirmed the content validity. There was high interrater reliability of the FSPT (r = .89; 95% CI, .85–.93; P < .001). FSPT total time (P = .001), penalty time (P = .022), and performance time (P = .001) were superior in elite relative to nonelite players. Anaerobic power was greater in elite players (P < .001). Conclusion: The results support the use of the FSPT to assess futsal players’ performance in conjunction with skill and anaerobic fitness.

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Ahmed Ismaeel, Michael Holmes, Evlampia Papoutsi, Lynn Panton and Panagiotis Koutakis

Resistance training is known to promote the generation of reactive oxygen species. Although this can likely upregulate the natural, endogenous antioxidant defense systems, high amounts of reactive oxygen species can cause skeletal muscle damage, fatigue, and impair recovery. To prevent these, antioxidant supplements are commonly consumed along with exercise. Recently, it has been shown that these reactive oxygen species are important for the cellular adaptation process, acting as redox signaling molecules. However, most of the research regarding antioxidant status and antioxidant supplementation with exercise has focused on endurance training. In this review, the authors discuss the evidence for resistance training modulating the antioxidant status. They also highlight the effects of combining antioxidant supplementation with resistance training on training-induced skeletal muscle adaptations.