Effects of Beet Juice on Performance in Competitive Swimmers

Abstract

Objective: This study analysed the effect of beetroot juice supplementation (BRJ) in an intermittent swimming session with high glycolytic demands on performance, biomechanical variables (speed, stroke length, cycle frequency, stroke index), blood lactate concentrations (BLa) and rating of perceived exertion (RPE). Design: a double-blind, placebo-controlled, crossover design participants ingested BRJ (~12.8 mmol of nitrate) or a placebo (PLA) in two different experimental sessions. Methods: 10 competitive adolescent swimmers (6 females and 4 males, range of age from 13 to 16 years) executing a swimming test consisting of an 8 x 50 m swimming protocol after taking BRJ or PLA. Biomechanics parameters, RPE after each set, and BLa pre and post-exercise were assessed. Results: BRJ enhanced the time in the swimming test (p=0.004) with a best medium time (p=0.004) and time in the slowest set (p=0.041). No differences were reported between BRJ and PLA for biomechanical parameters, BLa or RPE. Conclusions: BRJ enhanced swimming performance and the relationship between work and RPE, without any effect on the biomechanics parameters. Therefore, the intake of BRJ could be beneficial for swimmers along the high-intensity intermittent sessions