Acute beetroot juice ingestion fails to improve sprint performance and neuromuscular function in trained male sprinters: a randomized, double-blind, placebo-controlled study

Abstract

.

Introduction The aim of this study was to evaluate the acute effect of beetroot juice ingestion on sprint performance and neuromuscular properties of male trained sprinters.

Methods Twelve male sprinters (24.3 ± 4.8 years) participated in a randomized, double-blind, and placebo-controlled study with two experimental trials after the ingestion of 70 mL beetroot juice (containing 6.4 mmol NO3−) or 70 mL placebo drink (containing 0.04 mmol NO3−). Participants performed a countermovement jump, a squat jump, and 60 and 100 m sprint tests at 150 minutes after ingestion. Before and after these performance tests, contractile properties of the rectus femoris, biceps femoris, gastrocnemius lateralis, and gastrocnemius medialis muscles were measured with tensiomyography.

Results Salivary concentrations of NO3− and nitrite NO2− were also measured and in comparison to the placebo drink, the intake of beetroot juice increased salivary concentrations of NO3− (from 230 ± 435 vs 6164 ± 3370 μM; p = < 0.001, ES = 1.53) and NO2− (130 ± 131 vs 4509 ± 4895 μM; p = 0.018; ES = 1.63). Beetroot juice ingestion did not affect countermovement jump height (44.12 ± 6.14 vs 43.6 ± 6.29 cm; p = 0.400; ES = −0.25), squat jump height (42.02 ± 4.92 vs 41.91 cm; p = 0.911; ES = 0.04), 60 m sprint time (7.55 ± 0.32 vs 7.58 ± 0.32 seconds; p = 0.407; ES = −0.24), or 100 m sprint time (12.57 ± 0.65 vs 12.51 ± 0.62 seconds; p = 0.343; ES = 0.29). The tensiomyography analysis did not report any difference in the contractile properties of the muscles analyzed (p = 0.065–0.914), except for the biceps femoris in the relaxation time variable (p = 0.047).

Conclusion Acute ingestion of 70 mL beetroot juice containing 6.4 mmol of NO3− did not enhance sprint performance or the neuromuscular function of male trained sprinters.

Trial registration: The study was retrospectively registered in ClinicalTrials.gov with the following ID: 5-56NCT06675682 by 1 November 2024.