tailieunhanh - Báo cáo y học: " Ergogenic effects of betaine supplementation on strength and power performance"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Ergogenic effects of betaine supplementation on strength and power performance | Lee et al. Journal of the International Society of Sports Nutrition 2010 7 27 http content 7 1 27 jissn journal of the onal society of sports nutrition RESEARCH ARTICLE Open Access Ergogenic effects of betaine supplementation on strength and power performance 1 1 1 1 1 1 Elaine C Lee Carl M Maresh William J Kraemer Linda M Yamamoto Disa L Hatfield Brooke L Bailey Lawrence E Armstrong1 Jeff S Volek1 Brendon P McDermott1 Stuart AS Craig2 Abstract Background We investigated the ergogenic effects of betaine B supplementation on strength and power performance. Methods Twelve men mean SD age 21 3 yr mass kg with a minimum of 3 months resistance training completed two 14-day experimental trials separated by a 14-day washout period in a balanced randomized double-blind repeated measures crossover design. Prior to and following 14 days of twice daily B or placebo P supplementation subjects completed two consecutive days D1 and D2 of a standardized high intensity strength power resistance exercise challenge REC . Performance included bench squat and jump tests. Results Following 14-days of B supplementation D1 and D2 bench throw power 1779 90 and 1788 34 W respectively and isometric bench press force 2922 297 and 2503 28 N respectively were increased p during REC compared to pre-supplementation values 1534 30 and 1498 29 W respectively 2345 64 and 2423 84 N respectively and corresponding P values 1374 128 and 1523 39 W 2175 92 and 2128 56 N respectively . Compared to pre-supplementation vertical jump power and isometric squat force increased p on D1 and D2 following B supplementation. However there were no differences in jump squat power or the number of bench press or squat repetitions. Conclusion B supplementation increased power force and maintenance of these measures in selected performance measures and these were more apparent in the smaller upper-body muscle groups. Background As an organic osmoprotectant and source of methyl groups .