Does beta-alanine supplementation enhance adaptations to resistance training? A randomized, placebo-controlled, double-blind study.

The aim of the present study was to assess the effects of beta-alanine supplementation on muscle strength and thickness. Nineteen resistance-trained men (age: 27.3 ± 5.5 years; height: 178 ± 10 cm; body mass: 83.4 ± 9.7 kg; training experience: 5.9 ± 3.9 years) were allocated to one of the following groups: Beta-alanine (BA) (6.4 g/day of beta-alanine) or Placebo (PLA) (6.4 g/day of maltodextrin). Subjects completed 4 resistance training sessions per week for 8 weeks. The following assessments were performed before and after intervention periods: 1 repetition maximum (1RM) and 60%1RM tests in the bench press (60%1RMBENCH) and back squat (60%1RMSQUAT) exercises; muscle thickness assessment of biceps brachialis (MTBB), triceps brachialis (MTTB), and vastus lateralis (MTVL) by ultrasonography. No significant difference between groups was observed for the absolute increase (pre-post intervention) in the 1RMBENCH (mean difference = 0.8 kg; p = 0.679), 1RMSQUAT (mean difference = 0.1 kg; p = 0.992), MTBB (mean difference = 0.7 mm; p = 0.637), MTTB (mean difference = 1.4 mm; p = 0.282), MTVL (mean difference = 1.6 mm; p = 0.311), 60%1RMBENCH (mean difference = 0.5 repetitions; p = 0.670) and 60%1RMSQUAT (mean difference = 0.7 repetitions; p = 0.690). In conclusion, the 8-week training period induced significant strength and morphological responses. However, the addition of beta-alanine supplementation did not enhance these adaptive outcomes.

Tri-Set Training System Induces a High Muscle Swelling with Short Time Commitment in Resistance-Trained Subjects: A Cross-Over Study.

The purpose of the present study was to assess performance and morphological acute responses to the tri-set (TRI) resistance-training system. In a random order, 18 subjects (years: 30.0 ± 5.6; weight: 81.8 ± 13.4 kg; height: 173 ± 6.2 cm; RT experience: 4.6 ± 1.7 years) performed 3 exercises targeting the pectoralis major muscle in two different experimental conditions: traditional system (TRAD) and TRI. The TRAD protocol referred to the completion of a single exercise set followed by a rest period. For the TRI protocol, one set of each exercise was performed sequentially with a minimal rest interval afforded (< 10 seconds). Both protocols were performed in 3 sets of 10RM. Pectoralis major muscle swelling (PMMS), volume load (VL), internal training load (ITL) and training efficiency (TE) were calculated and compared between both protocols. Despite the low VL (-19.3%; p < 0.001), larger values of PMMS (104.7%; p < 0.001), ITL (24.3%; p < 0.001) and TE (56.0%; p < 0.001) were observed during TRI compared to TRAD condition. In conclusion, the adoption of a TRI training protocol may induce distinct performance and morphological acute responses compared to TRAD, suggesting that resistance-trained subjects may experience a higher muscle swelling and intensity of effort with short time commitment when performing TRI system.

Acute Effects of Inter-set Stretching on Performance and Metabolic Parameters of Resistance-trained Men.

The present study investigated acute muscular performance and metabolic responses to resistance training (RT) with inter-set stretching (ISS). Seventeen resistance-trained men (age: 30.0 ± 5.6 years; body mass: 81.8 ± 13.4 kg; height: 173 ± 6.2 cm; RT experience: 4.6 ± 1.7 years) completed the ISS and traditional training (TT) protocol seven days apart in a randomized order. In both protocols, 7 sets of the seated cable fly exercise were performed with a 10-repetition maximum (10-RM) load. During the ISS protocol, subjects completed inter-set passive static stretching of the agonist muscles for 45 seconds, while a passive rest (no stretching) was adopted for the same duration in the TT protocol. The change in maximal bench press strength (1-RM), muscle swelling (ultrasound) of the pectoralis major (PMMS), and blood lactate were assessed immediately following each protocol. Additionally, the total load lifted (TLL) and internal training load (ITL) were assessed in both protocols. There was no difference between protocols for the change in maximal bench press 1-RM (p > 0.05). There were higher values for PMMS (p < 0.05) and blood lactate (p < 0.05) following the TT versus the ISS protocol. The TT resulted in higher TLL (p < 0.05) and ITL values (p < 0.05) versus the ISS protocol. Resistance training with inter-set stretching results in lower acute performance and metabolic responses versus traditional training with passive rest between sets. Therefore, inter-set stretching might be applied within a periodized program on lower intensity days to reduce the overall stress of a session.

Twice-daily sessions result in a greater muscle strength and a similar muscle hypertrophy compared to once-daily session in resistance-trained men.

BACKGROUND: The present study investigated the mid-term effects of training muscle groups once- versus twice-daily on morphofunctional adaptations in trained men. METHODS: Participants were randomly assigned to 1 of 2 experimental groups: 1 daily session per muscle group (1S, N.=11), where every muscle group was trained once a day or 2 daily sessions per muscle group (2S, N.=12), where every muscle group was trained twice. Testing was conducted before intervention and after 8 weeks for maximal strength (1RM) and muscular endurance (60%1RM) for bench press and parallel back squat exercises, and muscle thickness (MT) of the biceps brachii, triceps brachii, vastus lateralis, anterior quadriceps and pectoralis major. RESULTS: The major findings were as follows: 1) the increase in 1RM back squat was significantly greater in 2S (∆=16.1%) compared to 1S (∆=7.8%) (P<0.05); 2) both groups significantly increased bench press 1RM (1S: ∆=4.6%; 2S: ∆=6.8%), back squat 60% 1RM (1S: ∆=19.0%; 2S: ∆=24.3%), bench press 60% 1RM (1S: ∆=15.4%; 2S: ∆=24.0%) and all MT outcomes (P<0.05 for all), with no differences between experimental groups (1S and 2S). CONCLUSIONS: This study provides evidence that a twice-daily resistance training augments lower-body muscular strength; however, the daily frequency does not seem to have any additive effect on upper-body muscular strength, muscular endurance, and muscle hypertrophy in trained men.

High Resistance-Training Volume Enhances Muscle Thickness in Resistance-Trained Men.

ABSTRACT: Brigatto, FA, Lima, LEdM, Germano, MD, Aoki, MS, Braz, TV, and Lopes, CR. High resistance-training volume enhances muscle thickness in resistance-trained men. J Strength Cond Res 36(1): 22-30, 2022-This study investigated the effects of different volumes of resistance training (RT) (8 weeks of 16, 24, and 32 weekly sets per muscle group) on muscular strength and hypertrophy. Subjects were pair-matched according to baseline strength and then randomly assigned to 1 of 3 experimental groups: 16 weekly sets per muscle group (G16, n = 9), 24 weekly sets per muscle group (G24, n = 9), or 32 weekly sets per muscle group (G32, n = 9). All other RT variables (e.g., exercise performed, exercise order, weekly frequency, range of repetitions, rest interval between sets and exercises, etc.) were maintained constant. The total load lifted was calculated for every RT session to compare the accumulated external training load among experimental groups across the intervention period. Testing was conducted before intervention (pre) and after 8-week (post-8) periods for maximal voluntary muscle strength (1 repetition maximum [1RM] test for bench press and parallel back squat exercises) and muscle thickness (MT) of the biceps brachii, triceps brachii, and vastus lateralis. The major findings were as follows: (a) all RT volumes increased bench press and parallel back squat 1RM and (b) all RT volumes increased the biceps brachii, triceps brachii, and vastus lateralis MT. The magnitude of increase in 1RM and MT of the lower body when training with 32 weekly sets per muscle group was higher than for 16 weekly sets per muscle group. The magnitude of the increase in MTTB was higher when training with 32 weekly sets than for 16 weekly sets.

Effect of Different Recoveries During HIIT Sessions on Metabolic and Cardiorespiratory Responses and Sprint Performance in Healthy Men.

ABSTRACT: Germano, MD, Sindorf, MAG, Crisp, AH, Braz, TV, Brigatto, FA, Nunes, AG, Verlengia, R, Moreno, MA, Aoki, MS, and Lopes, CR. Effect of different recoveries during HIIT sessions on metabolic and cardiorespiratory responses and sprint performance in healthy men. J Strength Cond Res 36(1): 121-129, 2022-The purpose of this study was to investigate how the type (passive and active) and duration (short and long) recovery between maximum sprints affect blood lactate concentration, O2 consumed, the time spent at high percentages of V̇o2max, and performance. Subjects were randomly assigned to 4 experimental sessions of high-intensity interval training exercise. Each session was performed with a type and duration of the recovery (short passive recovery-2 minutes, long passive recovery [LPR-8 minutes], short active recovery-2 minutes, and long active recovery [LAR-8 minutes]). There were no significant differences in blood lactate concentration between any of the recoveries during the exercise period (p > 0.05). The LAR presented a significantly lower blood lactate value during the postexercise period compared with LPR (p < 0.01). The LPR showed a higher O2 volume consumed in detriment to the active protocols (p < 0.001). There were no significant differences in time spent at all percentages of V̇o2max between any of the recovery protocols (p > 0.05). The passive recoveries showed a significantly higher effort time compared with the active recoveries (p < 0.001). Different recovery does not affect blood lactate concentration during exercise. All the recoveries permitted reaching and time spent at high percentages of V̇o2max. Therefore, all the recoveries may be efficient to generate disturbances in the cardiorespiratory system.

Acute Effect of Different Duration of Foam Rolling Protocols on Muscle Thickness, Pain Pressure Threshold, and Volume Load on Multiple Sets of Knee Extension.

Previous studies investigated the effects of foam rolling (FR) on measurements of strength and power. However, the acute effect of FR on muscle thickness (MT) and pressure pain threshold (PPT) after multiple sets of resistance exercise remains to be elucidated. The aim of the present study was to examine the effect of one and three minutes of quadriceps FR on muscle thickness (vastus lateralis [VL] and rectus femoris [RF]), pain threshold (VL and RF), and total load lifted (TLL) on multiple sets of knee extension. Nine resistance-trained men (age: 24.8 ± 5.2 years; height: 177 ± 7 cm; total body mass 77.7 ± 6.2 kg) participated the study. MT, PPT, and performance on multiple sets of knee extension were compared after performing passive recovery (CON), one minute (FR1), or three minutes of FR (FR3). A similar total training load among experimental conditions was observed. There was a greater increase on VL muscle thickness after FR3 when compared to CON and FR1. In addition, there was an increase on rectus femoris PPT two minutes post FR3, with no differences between conditions. These results indicate that longer duration FR-protocol may acutely increase muscle thickness of the vastus lateralis muscle without negatively affect the TLL and PTT.

Excess Post-Exercise Oxygen Consumption and Substrate Oxidation Following High-Intensity Interval Training: Effects of Recovery Manipulation.

The recovery manipulation during high-intensity interval training (HIIT) may have the potential to modulate the responses of post-exercise energy metabolism. The purpose of this study was to investigate how the type (i.e., passive and active) and duration (i.e., short and long) of the recovery between the intervals in HIIT affect the excess post-exercise oxygen consumption (EPOC) and oxidation of fats and carbohydrates during the post-exercise recovery. Eight physically active men performed a maximal incremental test, to determine the peak oxygen consumption (V̇O2peak) and the first ventilatory threshold (VT), and four HIIT exercise sessions on a treadmill. The HIIT exercise sessions consisted of 5 intervals interspersed with 4 recovery periods; each interval was sustained until exhaustion, and the intensity was set at the V̇O2peak velocity; recoveries were passive, active (VT velocity), short (2-min), or long (8-min). The HIIT exercise sessions were performed in a random and crossed manner. After the HIIT exercise sessions, EPOC and oxidation of fats and carbohydrates were measured during the 120-min of post-exercise recovery. There were no differences in the EPOC among the exercise sessions (p = 0.56). There were no differences among the exercise sessions in the amount of energy expended on the oxidation of fats (p = 0.78) and carbohydrates (p = 0.91) during the post-exercise recovery. The recovery manipulation during HIIT does not affect the EPOC and post-exercise fat and carbohydrate oxidation. One can choose the type and duration of recovery, knowing that the post-exercise substrate oxidation and EPOC responses will be preserved.

Multi-joint vs. Single-joint Resistance Exercises Induce a Similar Strength Increase in Trained Men: A Randomized Longitudinal Crossover Study.

The type of exercise is a relevant resistance training-variable that might be manipulated in order to induce significant increases in muscle strength. The aim of this study was to analyze the influence of multi-joint vs single-joint resistance exercises on maximal strength. Sixteen resistance-trained men (age: 23.1 ± 4.4 years; body mass: 86.0 ± 12.8; height: 177.9 ± 6.4 cm; training experience: 4.2 ± 3.4 years) performed one of the following training protocols for six weeks: MULTI, consisting of only multi-joint exercises or SINGLE, consisting of only single-joint exercises. Subjects were then submitted to a three-week washout period, before being submitted to the other protocol for another six weeks. A linear periodization model was adopted in which external load was increased and the repetition range was decreased every two weeks. Maximal dynamic strength of bench press (1RMBENCH) and squat exercises (1RMSQUAT), a percentage variation of total load lifted (ΔTLL) and internal training load (ITL) were measured. Similar increases in 1RMBENCH (MULTI: 10.8%, p < 0.001; SINGLE: 5.5%, p < 0.001) and 1RMSQUAT (MULTI: 19.7%, p < 0.001; SINGLE: 19.0%, p < 0.001) were observed after the MULTI and SINGLE protocols. A decrease in TLL was detected for both exercise protocols; however, the SINGLE protocol induced a greater decrease, compared to the MULTI protocol (-35 ± 11% vs -42 ± 5%, respectively; p = 0.026). A greater ITL for the MULTI was observed when compared to the SINGLE (12.1%; p < 0.001). In conclusion, resistance training protocols with different exercise modalities seem to produce similar strength increases in resistance-trained men.

High Resistance-Training Frequency Enhances Muscle Thickness in Resistance-Trained Men.

Zaroni, RS, Brigatto, FA, Schoenfeld, BJ, Braz, TV, Benvenutti, JC, Germano, MD, Marchetti, PH, Aoki, MS, and Lopes, CR. High resistance-training frequency enhances muscle thickness in resistance-trained men. J Strength Cond Res 33(7S): S140-S151, 2019-The purpose of this study was to compare the effect a split training routine with muscle groups trained once per week (SPLIT) vs. whole-body split training routine with muscle groups trained 5 days per week (TOTAL) on neuromuscular adaptations in well-trained men. Eighteen healthy men (height = 177.8 ± 6.6 cm; total body mass = 84.4 ± 8.1 kg; age = 26.4 ± 4.6 years) were recruited to participate in this study. The experimental groups were matched according to baseline strength and then randomly assigned to 1 of the 2 experimental groups: SPLIT (n = 9) or TOTAL (n = 9). Prestudy and poststudy testing included 1RM for bench press, parallel back-squat and machine close-grip seated row, as well as an ultrasound analysis of the muscle thickness (MT) of the elbow flexors, triceps brachii, and vastus lateralis. After 8 weeks of training, no significant difference between groups was noted for all 1RM tests (p > 0.05). TOTAL induced a significantly greater increase in MT of the forearm flexors and vastus lateralis (p < 0.05). In conclusion, muscle strength increment is similar regardless of the experimental conditions studied; however, TOTAL may confer a potentially superior hypertrophic effect.

Effect of Resistance Training Frequency on Neuromuscular Performance and Muscle Morphology After 8 Weeks in Trained Men.

Brigatto, FA, Braz, TV, Zanini, TCdC, Germano, MD, Aoki, MS, Schoenfeld, BJ, Marchetti, PH, and Lopes, CR. Effect of resistance training frequency on neuromuscular performance and muscle morphology after 8 weeks in trained men. J Strength Cond Res 33(8): 2104-2116, 2019-The purpose of this study was to investigate the chronic effects of training muscle groups 1 day per week vs. 2 days per week on neuromuscular performance and morphological adaptations in trained men with the number of sets per muscle group equated between conditions. Participants were randomly assigned in 2 experimental groups: 1 session·wk per muscle group (G1, n = 10), where every muscle group was trained once a week with 16 sets or 2 sessions·wk per muscle group (G2, n = 10), where every muscle group was trained twice a week with 8 sets per session. All other variables were held constant over the 8-week study period. No significant difference between conditions for maximal strength in the back squat or bench press, muscle thickness in the elbow extensors, elbow flexors, or quadriceps femoris, and muscle endurance in the back squat and bench press performed at 60% 1 repetition maximum was detected. Effect size favored G2 for some outcome measurements, suggesting the potential of a slight benefit to the higher training frequency. In conclusion, both G1 and G2 significantly enhance neuromuscular adaptations, with a similar change noted between experimental conditions.

Description of training loads using whole-body exercise during high-intensity interval training.

OBJECTIVES: To describe external training load and internal training load through sets of a single session of high-intensity interval training (HIIT) body work. METHODS: Twenty male individuals (24±3 years) performed a HIIT body work protocol consisting of a single bout of exercise with 1:1 stimuli. The exercises used were 30 min in duration with "all-out" intensity. The exercises included jumping jacks, mountain climbers, burpees and squat jumps, totaling 20 min of exercise. During exercise, total movement capacity, blood lactate measurement, ratings of perceived exertion and recovery, training load and intensity were monitored. RESULTS: The single bout examined showed a total of 382±89 movements. Differences (p<0.01) in the total amount of movement for each exercise were noted, reflecting the difficulty of maintaining exercise over time. Increases in lactate concentrations (before: 0.98±0.16, after: 14.10±1.66; mmol/L) were found postexercise. Significant differences (p<0.01) were found after the fifth set, and the values for movement capacity remained higher than the values of the first set, demonstrating high load in a single session. No differences in ratings of perceived exertion (RPE) during the sets were found. However, the ratings of perceived recuperation from the second set were significantly (p<0.01) lower than those from the first set. CONCLUSIONS: The exercise protocol used in this study was of high intensity and produced large values for stress during performance, with increases recorded for the internal load indicators.

Effect of Inspiratory Muscle Training on Performance of Handball Athletes.

Inspiratory muscle training (IMT) is a strategy that has been used to improve performance in different sports modalities. This study investigated the effects of an IMT program on respiratory muscle strength and resistance as well as aerobic physical performance (PP) of handball athletes. Nineteen 20 ± 3 year-old male athletes were allocated into an experimental (EG, n = 10) or a placebo group (PG, n = 9). Their respiratory muscle strength was evaluated by measuring the maximum inspiratory and expiratory pressures (MIP and MEP), muscular respiratory resistance by maximum voluntary ventilation (MVV) and aerobic PP by the cardiopulmonary exercise test. The study was designed to evaluate the effects of a 12-week IMT program with five sessions a week. A significant difference was observed in the pre and post IMT values of the MIP (170 ± 34 to 262 ± 33 cmH2O) and MEP (177 ± 36 to 218 ± 37 cmH2O) in the EG, and MIP (173 ± 45 to 213 ± 21 cmH2O) in the PG, with a large effect size for the MIP, when the groups were compared. MVV showed a significant increase (162 ± 24 to 173 ± 30 L) in the EG, with a small effect size. There was a significant difference in maximum oxygen uptake (54 ± 8 to 60 ± 7 ml/kg/min) in aerobic PP. Oxygen uptake at the respiratory compensation point (RCP) (46 ± 6 to 50 ± 5 ml/kg/min), with a moderate effect size for both variables, was observed in the EG after IMT. We concluded that IMT provided a significant increase in respiratory muscle strength and resistance, contributing to increased aerobic PP in the EG, which suggests that IMT could be incorporated in handball players' training.

Description of training loads using whole-body exercise during high-intensity interval training

OBJECTIVES: To describe external training load and internal training load through sets of a single session of high-intensity interval training (HIIT) body work. METHODS: Twenty male individuals (24±3 years) performed a HIIT body work protocol consisting of a single bout of exercise with 1:1 stimuli. The exercises used were 30 min in duration with "all-out" intensity. The exercises included jumping jacks, mountain climbers, burpees and squat jumps, totaling 20 min of exercise. During exercise, total movement capacity, blood lactate measurement, ratings of perceived exertion and recovery, training load and intensity were monitored. RESULTS: The single bout examined showed a total of 382±89 movements. Differences (p<0.01) in the total amount of movement for each exercise were noted, reflecting the difficulty of maintaining exercise over time. Increases in lactate concentrations (before: 0.98±0.16, after: 14.10±1.66; mmol/L) were found postexercise. Significant differences (p<0.01) were found after the fifth set, and the values for movement capacity remained higher than the values of the first set, demonstrating high load in a single session. No differences in ratings of perceived exertion (RPE) during the sets were found. However, the ratings of perceived recuperation from the second set were significantly (p<0.01) lower than those from the first set. CONCLUSIONS: The exercise protocol used in this study was of high intensity and produced large values for stress during performance, with increases recorded for the internal load indicators.

Effect of linear and undulating training periodization models on the repeated sprint ability and strength of soccer players

Purpose: The aim of the study was to investigate the effect of linear and undulating strength-power training scheme on the repeated sprint ability (RSA) and lower body strength of soccer players. Method: Twenty soccer players (under-20 category) were split into 2 groups: the linear load (LL, n=10) and the undulating load (UL, n=10). In the commencement and at the end of the 6-week pre-season period, the RSA test (6 x 35m) and the 1RM parallel squat test (1RMsquat) were conducted. The LL and UL performed the same type and number of sessions. The training stimulus in the strength training was different between LL (Weeks 1 and 2 = Muscular Endurance; Weeks 3 and 4 = Strength; Weeks 5 and 6 = Power) and UL (daily load variation in the same week). Results: A improvement in RSAmean and 1RMsquat was detected in LL and in UL. No significant difference was noted between LL vs UL for all variables. Conclusion: Both groups improved maximal muscle strength in parallel back squat and RSA. UL induced a greater gain in RSA.(AU)

Is the weekly sets volume training performed by trained subjects in accordance with training recommendations guidelines for muscle hypertrophy?

Abstract AIM the aim of this study was to analyze the weekly sets volume (WSV) performed by trained men and women for each muscle group in muscle hypertrophy programs. METHODS One hundred and five resistance training practitioners of both sex (42 women, 29.8±5.7 years; 63 men, 28.5±5.7 years) consented to the analysis of their current training programs. Their training plains were analyzed by a researcher that used the following equation to determine the WSV performed for each muscle group: "number of exercises per muscle group per training session X number of sets per exercise in each training session X weekly training frequency per muscle group". The median values ​​by each muscle group were compared within and between genders. RESULTS Between group analysis demonstrated that men performed higher WSV for upper body (UB) muscles than women (47.2±14,6 vs. 18.2±7.4 sets). Conversely, women performed a higher WSV for lower body (LB) muscle groups than men (23.8±11.2 vs. 11.5±7.0 sets). The training volume for the abdominal muscles did not differ between groups. When comparing the WSV for the UB, LB and core musculature within groups, men perform higher training volumes for the UB compared to the LB and core, while women train the LB with a higher volume compared to the other musculature. CONCLUSION For some muscle groups, the WSV is higher than recommended in the literature for muscle hypertrophy. Men emphasize the UB training, while women emphasize training the LB. Moreover, the WSV performed by subjects of both genders is disproportionate between different muscle groups.

Validation of the VERT wearable jump monitor device in elite youth volleyball players.

This technical report aims to determine the validity and the accuracy of the VERT Wearable Jump Monitor. The participants of this study were all experienced volleyball players from the U18 category from the Brazilian National team. To assess jump performance, the VERT scores were compared to the VERTEC (jump and reach device). Each athlete performed 3 attack and 3 block jumps in a random, counterbalanced order, and the average score was registered. In the attack jumps, the VERTEC and VERT mean ± SD scores were 70.9±8.2 and 76.3±7.5 cm, respectively, and the typical error of the estimate (TEE) as a coefficient of variation (CV) was 7.8% (90% CL 7.0 to 8.9%). VERTEC and VERT devices presented a very large Pearson's correlation for attack jumps (r=0.75; 90% CL 0.68 to 0.81). In addition, the mean±SD block jumps were 53.7±6.1 and 58.5±5.7 cm for the VERTEC and VERT, respectively and the TEE as a CV was 7.9% (90% CL 7.1 to 8.9%). Pearson's correlation coefficient was very large for block jumps (r=0.75; 90% CL 0.67 to 0.81). The VERT device was found to be a very practical tool to quantify jump performance in volleyball players.

Acute effect of different warm-up interventions on neuromuscular performance of recreational soccer players / Efeito agudo de diferentes intervenções de aquecimento pré-exercício sobre o desempenho neuromuscular de jogadores amadores de futebol

Pre-exercises interventions are frequently implemented in order to maximize athletic performance. In this sense, the aim of this study was to evaluated the effect of three distinct pre-exercise interventions on acute neuromuscular performance in recreational soccer players: 1) parallel squat; 2) static stretching; and 3) ballistic stretching. After all interventions, participants performed a flexibility evaluation (sit-and-reach-test), followed by a squat jump, a counter-movement jump and a 30 meter-sprint test. A one-way analysis of variance revealed: a) a significant decrease in jumping performance was induced by both Stretching conditions when compared to the parallel squat intervention; b) a significant increase in lower limb flexibility after both stretching interventions when compared to parallel squat. In conclusion, it is suggested that a pre-exercise intervention comprised of stretching exercises acutely increase flexibility, while may interfere in jump performance in recreational athletes...(AU)

Intervenções pré-exercício são frequentemente adotadas para maximizar o desempenho atlético. Nesse sentido, o objetivo deste estudo foi avaliar o efeito de três diferentes intervenções pré- exercício sobre o desempenho neuromuscular de jogadores de futebol amadores: 1) agachamento paralelo, 2) alongamento estático e 3) alongamento balístico. Após as intervenções, os participantes realizaram a avaliação de flexibilidade (teste de sentar e alcançar) e, em seguida, o salto com agachamento, o salto com contramovimento e o teste de velocidade de 30 metros. Os resultados da ANOVA one-way revelaram: a) redução significante no desempenho do salto para ambas às condições de alongamento quando comparadas ao agachamento paralelo e b) aumento significante da flexibilidade dos membros inferiores após ambas às intervenções de alongamento em comparação ao achamento paralelo. Em conclusão, sugere-se que as intervenções pré-exercício compostas de exercícios de alongamento aumentam agudamente a flexibilidade, paralelamente, podendo prejudicar o desempenho de saltos de atletas amadores...(AU)

Características e monitoramento do tapering no triathlon: uma revisão sistemática / Characteristics and monitoring of tapering in triathlon: a systematic review

O tapering é o momento da periodização em que a carga de treino é reduzida visando à minimização do estresse fisiológico, biomecânico e psicológico, acarretando a otimização da performance. O objetivo foi apresentar e discutir as características e monitoramento do tapering no triathlon. A partir dos critérios de seleção estabelecidos, foram encontrados 7 artigos. As evidências apontam que no tapering para triatletas treinados deve ocorrer redução do volume de treinamento na natação em torno de 41% a 60%, no ciclismo e corrida de 21% a 60%. Deve-se manter a intensidade durante o tapering com a utilização do tipo exponencial de queda rápida, durando de 8 a 14 dias no ciclismo e corrida, bem como, 21 dias na natação. O período pré tapering determina a magnitude dos efeitos do tapering, com expectativa do aumento de performance de 3% na competição...(AU)

Tapering is the time of periodization when training load is reduced in order to lower the physiological, biomechanical and psychological stress thus leading to an improved performance. This paper aims to present and discuss the characteristics and monitoring of taper in triathlon. According to the established search criteria, 7 papers were found. Current evidence show that volume training should be lowered in 41% to 60% for swimming and 21% to 60% for cycling and running in the tapering for trained triathletes. Training intensity must be maintained during rapid exponential fall mode taper. It should last from 8 to 14 days for running and cycling and 21 days for swimming. The pre tapering period determines the magnitude of tapering results, and a 3% performance increase is expected in the competition...(AU)

Kinematic and sEMG Analysis of the Back Squat at Different Intensities With and Without Knee Wraps.

The purposes of this study were to measure the acute effects of knee wraps (KWs) on knee and hip joint kinematics, dynamic muscle activation from the vastus lateralis (VL) and gluteus maximus (GM), and rating of perceived exertion (RPE) during the back squat exercise at 2 different intensities. Fourteen resistance-trained men (age: 24 ± 4 years, height: 176 ± 6 cm, body mass: 81 ± 11 kg, back squat 1 repetition maximum [1RM]: 107 ± 30 kg, 3 ± 1 year of back squat experience) performed 1 set of 3 repetitions under 4 different conditions, to a depth of approximately 90 degrees of knee joint flexion, and in random order: KWs at 60% 1RM (KW60), KWs at 90% 1RM (KW90), without knee wraps (NWs) at 60% 1RM (NW60), and NWs at 90% 1RM (NW90). The dependent variables obtained were vertical and horizontal bar displacement, peak joint angle in the sagittal plane (hip and knee joints), concentric and eccentric muscle activation (by integrated electromyography) from the VL and GM, and RPE. For muscle activity, there were significant decreases in the VL NWs at 60% 1RM (p = 0.013) and a significant increase NWs at 90% 1RM (p = 0.037). There was a significant increase in VL muscle activity at 90% 1RM, when compared with 60% 1RM (KW: p = 0.001, effect size (ES) = 1.51 and NW: p < 00.001, ES = 1.67). There was a decrease in GM muscle activity NWs only at 60% 1RM (p = 0.014). There was a significant increase in GM muscle activity at 90% 1RM, when compared with 60% 1RM (KW: p < 0.001 and NW: p < 0.001). For peak hip joint flexion angle, there was significant decreases between intensities (90% 1RM < 60% 1RM) only to NWs condition (p = 0.009), and there was greater knee flexion NWs for both intensities: 60% 1RM (p < 0.001) and 90% 1RM (p = 0.018). For normalized vertical barbell displacement, there were significant differences between intensities when using KWs (p = 0.022). There were significant differences in RPE between 60 and 90% 1RM for each condition: KWs (p < 0.001) and NWs (p < 0.001). In conclusion, the use of KWs results in decreased muscle activation of the VL at the same intensity (90% 1RM).