PURPOSE: Betaine is a naturally occurring protein that has been associated with a number of different cellular functions ranging from macromolecular organization of cell particles to energy production interfacing with endocrine function in humans. One important target tissue is skeletal muscle and therefore the purpose of this study was to examine the influence of betaine supplementation on performance, and on endocrine function following an acute exercise bout comprised of various exercise and work tasks known to stimulate skeletal muscle fiber recruitment. METHODS: Twelve healthy, recreationally weight-trained college men (Height 185.8 ± 33.7 cm Body Mass 68.0 ± 2.2 kg, %Fat 19.7 ± 1.2) volunteered for the study. We used a balanced, randomized, double-blind, crossover experimental design with subjects ingesting either 1.5g (2x/day) Betaine or placebo supplements. After familiarization with the exercises, subjects performed the acute exercise/work bout before and after 2 weeks of supplementation. After a 2-week washout period, the subjects repeated the study with the other supplement treatment. The acute exercise/work bout testing consisted of 10 maximal vertical jumps, a maximal isometric squat and isometric bench press, and a 10-minute box lift test (20.45 kg box lifted to 1.32 m platform). Blood samples were obtained from an antecubital vein by venipuncture prior to exercise, mid-way through, and then immediately, 5-minutes and 15-minutes post exercise. Data were analyzed using an analysis of variance with repeated measures and the alpha level was set at P ≤ 0.05. RESULTS: The 2 weeks of betaine supplementation significantly increased the change in isometric squat strength (160.25 ± 481.9 N versus −18.58 ± 493.8 N, p<0.05) and performance in the box lift test (0.83 ± 6.8 boxes/10-min versus −2.92 ± 5.79 boxes/10-min, p = 0.01). Additionally, betaine supplementation, versus the placebo, was associated with a significantly greater post-test area-under-the-curve (AUC, p<0.05) for the GH response to the exercise/work bout (52.03 ± 11.9 μg/L versus pre-test of 48.73 ± 9.8 μg/L and versus placebo post-test 49.8 ± 13.2 μg/L). The IGF AUC response was significantly greater in the post-test (132.12 ± 16.3 nmol/L) versus pre-test (122.74 ± 14.28 nmol/L) for betaine, and versus the post-test (119.04 ± 17.34 nmol/L) of the placebo supplement trail. The cortisol AUC was significantly decreased, p<0.05, in the betaine post-test (1059.29 ± 116.7 nmol/L) versus pre-test (1172.32 ± 132.1 nmol/L) and versus the post-test (1092.5 ± 161.1 nmol/L) for the placebo supplement trial. Conclusion: Dietary supplementation of 1.5 g, twice daily, of Betaine provides for an increase in isometric force production, work capacity and a positive anabolic endocrine responses to exercise when compared to changes observed during the placebo treatment conditions. Practical Applications: Dietary supplementation with 1.5 g of Betaine twice per day may contribute to enhanced energy production, force production and recovery from maximal and exhausting demanding exercise/work tasks in trained men.
1Human Performance Laboratory, University of Connecticut, Storrs, CT; and 2Danisco A/S Inc., Tarrytown, NY