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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.

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Iñigo Mujika and Ritva S. Taipale

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Martin C. Waller, Deborah A. Kerr, Martyn J. Binnie, Emily Eaton, Clare Wood, Terreen Stenvers, Daniel F. Gucciardi, Carmel Goodman and Kagan J. Ducker

The authors aimed to update knowledge of the use of supplements among Australian athletes at a state-based sports institute. The authors conducted a cross-sectional survey using an online questionnaire to assess the influence of age, sports category, and scholarship category on supplement use. Of 94 completed questionnaires, 82 (87%) indicated supplements in the previous 12 months (mean = 4.9 ± 3.3). No significant difference in supplement usage rate was identified when considering age, scholarship category, or sport category. The most frequently used supplements were sports drinks (70%), caffeine (48%), protein powder (42%), and sports bars (42%). Recovery (63%), health maintenance (59%), and improved energy (50%) were the most frequently reported rationale to use supplements. Allied health professionals and credible online resources were the predominant sources of influence regarding use. However, athletes from lower scholarship categories were more likely to have social media, parents, and siblings influence usage, and age was inversely related to increased influence from parents, social media, physicians not associated with the institute, the Internet, and siblings. Older athletes and those on higher scholarships were more likely to source supplements from training facilities and sports nutrition staff outside of the institute or direct from a supplier, whereas those on lower scholarships tended to rely more on family and friends for their supplements. Findings from this study show a high prevalence of supplement use and are the first to show an influence of social media, particularly in younger athletes. Opportunities exist to optimize how athletes are informed regarding supplement use and organizational and supplement policy.

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Gabriella Berwig Möller, Maria Júlia Vieira da Cunha Goulart, Bruna Bellincanta Nicoletto, Fernanda Donner Alves and Cláudia Dornelles Schneider

The aim of this study was to conduct a systematic review of the effects of probiotic supplementation on physically active individuals. The participants, interventions, comparisons, outcome and study design inclusion criteria were (a) studies involving healthy adults or older subjects of both sexes who did physical exercise (including athletes and physically active individuals), (b) interventions with probiotics, (c) inclusion of a control group, (d) outcomes not previously defined, and (e) clinical trials and randomized clinical trials, with no language or date restrictions. The search was conducted in the following scientific databases: MEDLINE, Embase, SciELO, Scopus, and Lilacs. Search terms were “Probiotics” OR “Prebiotics” OR “Microbiota” AND “Exercise” OR “Athletes.” The articles were first screened by title and abstract by two independent reviewers and disagreements resolved by a third reviewer. Data were extracted independently by the same two reviewers; results were extracted in duplicate and then compared to avoid errors. A total of 544 articles were retrieved and 24 were included. A total of 1,680 patients were included, most of them being male (n = 1,134, 67.5%), with a mean age of 30.9 ± 6.1 years. Following probiotic supplementation, positive effects have been reported for several outcomes including respiratory tract infection, immunologic markers, and gastrointestinal symptoms in both athletes and nonathletes. However, published studies have distinct protocols and measured outcomes, and some of them have small sample size and failed to prove beneficial effect on probiotic supplementation, leading to inconclusive results for standardized supplementation protocols.

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Iñigo Mujika, Luis Villanueva, Marijke Welvaert and David B. Pyne

Context/Background: International-level swimmers periodize their training to qualify for major championships, then improve further at these events. However, the effects of various factors that could affect performance progressions have not been described systematically. Purpose: To quantify the pattern of change in performance between season best qualifying time and the major championships of the year and to assess the influence of time between performance peaks, ranking at the major events, stroke, event distance, sex, age, and country. Methods: A total of 7832 official competition times recorded at 4 FINA World Championships and 2 Olympic Games between 2011 and 2017 were compared with each swimmer’s season best time prior to the major event of the year. Percentage change in performance was related with the time elapsed between season best and major competition, race event, sex, age, and country using linear mixed modeling. Results: Faster performance (−0.79% [0.67%]; mean [SD]) at the major competition of the year occurred in 38% of all observations vs 62% no change or regression (1.10% [0.88%]). The timing between performance peaks (<34 to >130 d) had little effect on performance progressions (P = .83). Only medal winners (−0.87% [0.91%]), finalists (−0.16% [0.97%]), and US swimmers (−0.44% [1.08%]) progressed between competitions. Stroke, event distance, sex, and age had trivial impact on performance progression. Conclusions: Performance progressions at Olympic Games and World Championships were not determined by timing between performance peaks. Performance progression at a major competition appears necessary to win a medal or make the final, independent of race event, sex, and age.