Acute beetroot juice administration improves peak isometric force production in adolescent males

作者:Bender David; Townsend Jeremy R*; Vantrease William C; Marshall Autumn C; Henry Ruth N; Heffington Stephen H; Johnson Kent D
来源:Applied Physiology Nutrition and Metabolism, 2018, 43(8): 816-821.
DOI:10.1139/apnm-2018-0050

摘要

The purpose of this study was to examine the effects of acute beetroot juice (BR) administration on repeated sprint performance and isometric force production in adolescent males. Twelve male adolescents (age, 16.8 +/- 1.0 years; height, 178.8 +/- 9.2 cm; mass, 74.8 +/- 12.5 kg; peak height velocity, 2.53 +/- 1.2 years) participated in this double-blind, placebo-controlled, crossover designed study. Participants consumed 2 x 70 mL of BR (similar to 12.9 mmol NO3-, Beet It Sport) or a nitrate-depleted placebo (PL) at 2.5 h prior to performing isometric mid-thigh pulls (IMTP) and 4 repeated 20-s Wingate sprints interspersed with 4 mm of rest. Sprint data were analyzed by a 2 x 4 (group x time) repeated-measures ANOVA while a dependent t test was used to compare conditions for IMTP peak force. A significant main effect for time (p < 0.05) was observed for peak power (PP), average power (P-avg), and fatigue index (FI) across sprints. Compared with sprint 1, sprint 4 resulted in significant decreases in PP (p < 0.000; -16.6%) and P-avg (p = 0.000; -21.8%) and FI was significantly elevated (p < 0.000;15.2%) No significant group x time interactions were observed between conditions tor PP (p = 0.402), P-avg (p = 0.479), or FI (p = 0.37). IMTP peak force was significantly higher (p = 0.004; 13.9%) following BR consumption compared with PL. The repeated sprint protocol resulted in significant fatigue while BR did not influence sprint performance. However, it appears BR administration may improve peak force production in adolescent males.

  • 出版日期2018-8