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, 79.1 +/- 10.7 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 < 0.05) 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 < 0.05) 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.