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PURPOSE: Melatonin supplementation has been disclosed as an ergogenic substance. However, the effectiveness of melatonin supplementation in healthy subjects has not been systematically investigated. The present study analyzed the effects of melatonin supplementation on physical performance and recovery. In addition, it was investigated whether exercise bout or training alter melatonin secretion in athletes and exercise practitioners. METHODS: This systematic review and meta-analysis were conducted and reported according to the guidelines outlined in the PRISMA statement. Based on the search and inclusion criteria, 21 studies were included in the systematic review, and 19 were included in the meta-analysis. RESULTS: Melatonin supplementation did not affect aerobic performance relative to time trial (-0.04; 95% CI: -0.51 to 0.44) and relative to VO2 (0.00; 95% CI: -0.57 to 0.57). Also, melatonin supplementation did not affect strength performance (0.19; 95% CI: -0.28 to 0.65). Only Glutathione Peroxidase (GPx) secretion increased after melatonin supplementation (1.40; 95% CI: 0.29 to 2.51). Post-exercise melatonin secretion was not changed immediately after an exercise session (0.56; 95% CI: -0.29 to 1.41) and 60 min after exercise (0.56; 95% CI: -0.29 to 1.41). CONCLUSION: The data indicate that melatonin is not an ergogenic hormone. In contrast, melatonin supplementation improves post-exercise recovery, even without altering its secretion.

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BACKGROUND: This study investigated the effects of two 14-week resistance training protocols with different repetition duration (RD) performed to muscle failure (MF) on gains in strength and muscle hypertrophy as well as on normalized electromyographic (EMG) amplitude and force-angle relationships. METHODS: The left and right legs of ten untrained males were assigned to either one of the two protocols (2-s or 6-s RD) incorporating unilateral knee extension exercise. Both protocols were performed with 3-4 sets, 50-60% of the one-repetition maximum (1RM), and 3 min rest. Rectus femoris and vastus lateralis cross-sectional areas (CSA), maximal voluntary isometric contraction (MVIC) at 30o and 90o of knee flexion and 1RM performance were assessed before and after the training period. In addition, normalized EMG amplitude-angle and force-angle relationships were assessed in the 6th and 39th experimental sessions. RESULTS: The 6-s RD protocol induced larger gains in MVIC at 30o of knee angle measurement than the 2-s RD protocol. Increases in MVIC at 90o of knee angle, 1RM, rectus femoris and vastus lateralis CSA were not significant between the 2-s and 6-s RD protocols. Moreover, different normalized EMG amplitude-angle and force-angle values were detected between protocols over most of the angles analyzed. CONCLUSION: Performing longer RD could be a more appropriate strategy to provide greater gains in isometric maximal muscle strength at shortened knee positions. However, similar maximum dynamic strength and muscle hypertrophy gains would be provided by protocols with different RD.

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This study investigated how different manual therapies applied to the posterior thigh muscles affect the ten-repetitions maximum performance test (10 RM) and hip flexion range-of-motion among young soccer players. Seventeen non-professional male soccer players performed the 10RM and range of motion pre-testing, and, in separate laboratory visits, they underwent three different experimental activities presented to each participant in a randomized order: (a) rest control activity with no intervention, (b) manual massage, and (c) muscle energy. Comparing pre-testing performances to repeated tests after each intervention condition, participants increased their maximum load lift on the 10-repeitions maximum test following manual massage and muscle energy interventions (p < 0.05), but not following the control condition. They also increased their hip range-of-motion on flexibility testing following manual massage and muscle energy (p < 0.05), but not following the control condition. Thus, both manual massage and muscle energy therapies applied to the posterior thigh were beneficial to performance. This finding has clear implications when preparing athletes for competition.

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A aplicação de uma adequada carga de treinamento é um dos fatores fundamentais para proporcionar adaptações positivas com consequente melhora do desempenho. O método da percepção subjetiva de esforço (PSE) após da sessão tem sido proposto como uma das melhores alternativas para quantificar a carga de reinamento (CT), principalmente pela sua fácil compreensão e a pela sua relativa simplicidade. O objetivo do presente estudo de caso foi quantificar a magnitude da CT através da PSE da sessão em dois atletas amadores de CrossFit® e comparar a carga de treinamento com outras modalidades esportivas. A carga de treinamento média durante as 11 semanas foram 173,5 UA (unidade arbitrárias) para o sujeito A e 190,6 UA para o sujeito B. Após á análise de diversos estudos que avaliaram a CT média pelo método da PSE da sessão, todos os esportes apresentaram scores da PSE da sessão maiores doque os observados no treino de CrossFit® utilizado no presente estudo. Em conclusão, os resultados apresentados sugerem que o método da PSE da sessão é capaz de distinguir diferentes cargas de treinamento em momentos de polimento, sobrecarga e recuperação, além disso, cada atleta apresenta uma resposta característica, o que ajuda a individualizar as análises...(AU)

The application of the appropriate training load (TL) is one of the fundamental factors to allow positive adaptations accompanied by improve in performance. The rating of perceived exertion (RPE) method of the session has been proposed as one of the best alternatives to quantify the TL, mainly due to the easy comprehension and relatively simplicity. The aim of the present case-study was to quantify the magnitude of the TL through RPE of the session in two CrossFit® athletes and to compare the TL with other training modalities. The mean training loads during the 11 weeks were 173.5 AU (arbitrary units) for the subject A and 190.6 AU for the subject B. After the analysis of several studies which evaluated the mean TL by the session RPE, all training modalities presented higher scores of session RPE as compared with the CrossFit® training used in the present study. In conclusion, the results presented suggest that the session RPE is able to distinguish different TL at times of tapering, overloading and recovery. In addition, each athlete presents a characteristic response, which helps to individualize the results...(AU)

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