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Volume 34 (2024): Issue 6 (Nov 2024)

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Volume 19 (2024): Issue 11 (Nov 2024)

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Effects of Training Volume in the Bench-Press Exercise Performed With Interrepetition Rest Periods on Strength Gains and Neuromuscular Adaptations

José A. Páez-Maldonado, Claro Cano, Pedro J. Cornejo-Daza, Juan Sánchez-Valdepeñas, Luis Rodiles-Guerrero, Mathias Wernbom, Manuel Ortega-Becerra, and Fernando Pareja-Blanco

Purpose: To investigate the effects of 3 training volumes in the bench-press exercise performed with interrepetition rest periods, matched for fatigue, on strength gains and neuromuscular adaptations. Methods: Forty-three resistance-trained men were randomized into 3 groups: low (LOW), moderate (MOD), and high (HIG) volume. The intensities increased from 70% to 85% of 1-repetition maximum (1RM) over the 8-week training period. Each session consisted of only 1 set with short interrepetition rest periods. LOW performed only 3 repetitions per session (8-wk total: 48 repetitions); MOD completed 15, 12, 10, and 8 repetitions per session with 70%, 75%, 80%, and 85% 1RM, respectively (8-wk total: 180); and HIG performed 24, 21, 18, and 15 repetitions per session with 70%, 75%, 80%, and 85% 1RM, respectively (8-wk total: 312). Progressive loading and fatigue tests were conducted in the bench-press exercise before and after the training period. Electromyography (EMG) signals from the triceps brachii were registered during these tests. Results: HIG and MOD showed higher velocity loss than LOW (16% vs 12%). No significant group × time interaction was observed for any variable. All groups improved significantly in all strength-related variables, except for maximal unloaded velocity, where only MOD obtained significant gains. Only LOW and MOD induced significant improvements in EMG. MOD obtained the greatest effect sizes in almost all strength variables. Conclusions: No significant differences were found in the performance gains obtained by each group despite the wide differences in the total volume accumulated by each group.

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Body Mass Management Practices of Olympic Weightlifting Athletes

Amie M. Cox, Carl Langan-Evans, David Jenkins, Reid Reale, Fiona Pelly, and Gary J. Slater

This study explored the body mass (BM) management practices among competitive male and female Olympic weightlifting athletes, hypothesizing that athletes compete in lighter weight categories than their habitual training weight (i.e., making weight). Utilizing a validated, anonymous survey, data were collected from 149 Olympic weightlifting athletes (>18 years; female = 94). The survey comprised five sections: demographics, training/competition history, weight history, source of influence, and BM management practices. The prevalence, magnitude, and methods employed for BM management were analyzed with subgroup analysis using one-way analysis of variance. Post hoc testing including Spearman’s rho and chi-square analysis was completed when a significant effect was found. Three quarters (76%) of athletes acknowledged using chronic weight loss and/or acute weight loss strategies to make weight. Usual BM loss (2%–3%) in the week before competition was within recommended guidelines. Gradual dieting, fluid restriction, and low food weight, high-calorie options were the most commonly used BM management strategies. Female athletes were more likely to use gradual dieting (p = .043; r = .104) and were less likely to increase their exercise (p = .046; r = −.105) and utilize fasting (p = .038; r = .05) compared with their male counterparts. Women further identified dietitians/nutritionists (p = .006; r = .022) as a highly influential source of information. This research offers new insights into the BM management practices of Olympic weightlifting athletes, identifying that the majority of athletes compete at a BM lighter than their habitual training weight, achieved using a range of chronic weight loss and acute weight loss strategies.

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Factors Informing Training Load During the Transition From Club to National Football Teams

Joshua J Gould, Ewan Clements, Fabian Ehrmann, and Rob Duffield

Purpose: This study examined the relationship of precamp match exposure, travel demands, perceptual wellness, and musculoskeletal screening with ensuing training load (TL) during national-team (NT) duties for international footballers (soccer). Methods: Match minutes and days since last match prior to NT arrival were collected for match exposure. Travel duration and time-zone difference were included as travel demands. Perceptual fatigue, soreness, sleep quality, and stress scores were collected via self-report questionnaire on arrival to NT. Musculoskeletal testing on day 1 of NT included knee to wall and hip internal and external rotation. Relative TL across the first 3 days of NT camp was measured via total distance, high-speed running distance, very high-speed running distance, and accelerations and decelerations per minute. Linear mixed models determined the influence of independent variables on respective TL metrics, with the player included as a random effect. Results: Total distance, high-speed running, very high-speed running, and decelerations per minute were all highest on day 3 (P < .001). Small relationships existed (R 2 < .15) between decreased total distance per minute and increased soreness (P = .037), while decreased high-speed running per minute was associated with increased fatigue (P = .017). Small associations existed between decreased accelerations per minute, increased hip internal rotation (P < .001), fatigue (P = .033), and knee to wall (P = .016), while decreased decelerations per minute were associated with increased soreness (P = .001), knee to wall (P = .024), and days between recent match and arrival (P = .003). Conclusions: Very small relationships existed between fatigue, soreness, musculoskeletal screening, and prior match exposure with TL. The larger influence of camp day suggests that deliberate periodization of training is a major factor for prescription on arrival into NT duties.

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Greater Relative First and Second Lactate Thresholds in Females Compared With Males: Consideration for Exercise Prescription

José Antonio Benítez-Muñoz, Miguel Ángel Rojo-Tirado, Pedro José Benito Peinado, Juan M. Murias, Domingo González-Lamuño, and Rocío Cupeiro

Purpose: To investigate differences between females and males at lactate thresholds 1 (LT1) and 2 (LT2). Methods: Twenty-four female and twenty male participants performed an incremental cycle-ergometer test until exhaustion, where LT1 and LT2 were determined in each volunteer. Results: Power output at LT1 and LT2 was lower in females than in males (P < .001). In addition, power output relative to peak power was higher in females at LT1 and LT2 (P < .001). However, heart rate was higher in females than males at LT1 and LT2 (P = .008). Furthermore, the heart rate relative to maximal heart rate was higher in females compared with males at LT1 and LT2 (P = .002). Conclusion: Females and males may be in a different metabolic situation at the same percentage of maximum. This study helps to reduce sex bias in science, and future guidelines should consider establishing exercise prescription recommendations according to sex. Clinical Trial: NCT06104150.

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Neuromuscular Fatigue During Brazilian Jiujitsu Matches: Analysis of Upper and Lower Limbs

Athos da Silva Fagundes, Alisson Henrique Marinho, Iron Lopes Freitas, Brandel José Pacheco Lopes Filho, Cintia Rodacki, Romulo Bertuzzi, Adriano Eduardo Lima-Silva, and Gislaine Cristina-Souza

Purpose: To determine the effects of repeated Brazilian jiujitsu (BJJ) matches on neuromuscular fatigue in forearm-flexor and knee-extensor muscles. Methods: Twelve BJJ athletes (8 men and 4 women) performed a simulated BJJ tournament composed of four 8-minute matches interspersed by 16-minute intervals. Neuromuscular fatigue was assessed via prematch to postmatch(es) reductions in maximal voluntary isometric contraction (MVIC), voluntary activation, and potentiated twitch force (Ptwpot) in the forearm-flexor and knee-extensor muscles. Results: The MVIC of the knee extensors and forearm flexors reduced from prematch 1 to postmatch 2 and remained suppressed until postmatch 4 (P < .034). The voluntary activation of the knee extensors declined only after match 4, whereas the voluntary activation of the forearm flexors did not change throughout the matches (P = .102). Ptwpot of knee extensors decreased from prematch 1 to postmatch 1 (P < .001) and remained reduced until postmatch 4 (P < .001). Ptwpot of the forearm flexors reduced after every match (P < .010), with complete recovery occurring only before the second match (P = .99). The magnitude of the prematch-to-postmatch reduction in Ptwpot was lower in knee extensors than in forearm flexors (P = .044). Conclusions: Repeated BJJ matches induced neuromuscular fatigue, mainly due to impairments in muscle contractile function (ie, peripheral fatigue). The time between BJJ matches seems to be insufficient to allow complete recovery of neuromuscular function, which may influence performance during subsequent matches.

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Influence of Menstrual-Cycle Phase on Sleep and Recovery Following High- and Low-Intensity Training in Eumenorrheic Endurance-Trained Women: The Female Endurance Athlete Project

Madison Y. Taylor, Maria Hrozanova, Liv Nordengen, Øyvind Sandbakk, John O. Osborne, and Dionne A. Noordhof

Purpose: To investigate the influence of menstrual-cycle (MC) phase on objective sleep and perceived recovery following high- (HIT) and low-intensity training (LIT) in endurance-trained women. Methods: Fifteen naturally menstruating, endurance-trained women completed standardized HIT and LIT sessions during the early follicular phase (EFP), ovulatory phase (OP), and midluteal phase (MLP) of 2 MCs. Overnight sleep was monitored using a Somnofy sleep monitor after each training session, and perceived recovery was assessed after 24 hours using self-report scales. MC phases were determined using the 3-step method, and noneumenorrheic MCs were retrospectively excluded from analysis. Results: MC phase had a main effect on wake after sleep onset (P ≤ .001), with higher values in MLP (33 [22] min) than EFP (22 [19] min, P = .043) and OP (14 [9] min, P = .001), sleep efficiency (P = .033), with lower values in MLP (87% [6%]) than OP (90% [8%], P = .047), and light sleep (P = .023) with higher values in MLP (59% [6%]) than EFP (54% [7%], P = .037). Session type had a main effect on perceived recovery (P < .018) and perceived muscle soreness (P = .007), indicating lower perceived recovery and higher perceived muscle soreness following HIT compared to LIT (P < .001, P = .018, respectively). No interactions were found between MC phase and session type for any of the measured variables. Conclusions: Objective sleep quality, but not perceived recovery, was influenced by MC phase, as indicated by small impairments to multiple indices of objective sleep during MLP. There were no interactions between MC phase and session type, indicating that the effect of MC on sleep and recovery is consistent regardless of session type.

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Acute Effects of Taurine Supplementation on Maximal Fat Oxidation and FATmax in Recreational Endurance Runners: A Randomized, Placebo-Controlled, Crossover, and Triple-Blinded Study

Abdolrahman Ghazzagh, Alireza Naderi, Hamid Agha-Alinejad, Ali Livani, Mohsen Sarlak, Samaneh Aghamohammadi, and Bryan Saunders

Taurine (TAU) has been shown to improve time to exhaustion (TTE) and fat oxidation during exercise; however, no studies have examined the effect of acute TAU supplementation on maximal fat oxidation (MFO) and related intensity to MFO (FATmax). Our study aimed to investigate the effect of acute TAU supplementation on MFO, FATmax, VO2peak, and TTE. Eleven recreationally trained male endurance runners performed three incremental running tests. The first visit included a familiarization to the test, followed by two subsequent visits in which exercise was performed 90 min after ingestion of either 6-g TAU or placebo (PLA) using a triple-blind randomized crossover design. There was no effect of TAU on MFO (p = .89, d = −0.07, TAU: 0.48 ± 0.22 g/min; PLA: 0.49 ± 0.15 g/min or FATmax (p = .26, d = −0.66; TAU: 49.17 ± 15.86 % V ˙ O 2 peak ; PLA: 56.00 ± 13.27 % V ˙ O 2 peak ). TTE was not significantly altered (TAU: 1,444.8 ± 88.6 s; PLA: 1,447.6 ± 87.34 s; p = .65, d = −0.04). TAU did not show any effect on V ˙ O 2 peak in comparison with PLA (TAU: 58.9 ± 8.4 ml·kg−1·min−1; PLA: 56.5 ± 5.7 ml·kg−1·min−1, p = .47, d = 0.48). However, V ˙ O 2 TAU at most stages of exercise with large effect sizes ( η p 2 = .43 ). The acute ingestion of 6 g of TAU before exercise did not enhance MFO, FATmax, or TTE. However, it did increase the oxygen cost of running fixed intensities in recreationally trained endurance runners.

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Assessing the Use of Recommended Practices in Adapted Physical Activity/Education Experiential-Learning Programs

Layne Case, Joonkoo Yun, Megan MacDonald, Bridget E. Hatfield, and Samuel W. Logan

This study investigated the use of recommended practices in university-based experiential learning associated with adapted physical activity and education (APA/E) undergraduate courses. Participants (N = 165) were instructors of APA/E courses with an experiential-learning component and/or professionals involved in APA/E experiential-learning programs at their university. Participants completed an online questionnaire designed to describe program characteristics and evaluate the use of two sets of practices, including those recommended for involving students and people with disabilities. Findings highlight low proportions of the use of practices recommended for people with disabilities and indicate that significantly more practices recommended for students were implemented (Z = −10.45, p < .001). Findings from this study have several implications for evaluation and intervention in APA/E experiential learning, such as including the disability community in planning and designing programming to benefit both students and people with disabilities. Instructors should aim to increase their implementation of practices recommended for involving people with disabilities.