The aim of this study was to examine the effects of multiday beetroot juice ingestion on neuromuscular performance in semi-professional, male handball players. Twelve handball players competing in the second Spanish national division received 70 ml of beetroot juice (6.4 mmol of nitrate [NO3-]) or 70 ml of a placebo beetroot juice (0.04 mmol NO3-) for three consecutive days in a randomized, double-blind, crossover manner with a 1-week washout between conditions. Following supplementation in each condition, players completed a neuromuscular test battery involving handball throwing, isometric handgrip strength, countermovement jump, change-of-direction speed, and repeated-sprint assessments, with side effects also measured. Countermovement jump (4.7%; p = .038; Hedge's gav = 0.29) and isometric handgrip strength (7.8%; p = .021; gav = 0.59) were significantly superior with beetroot juice ingestion compared to the placebo. In contrast, nonsignificant differences were evident between conditions for all other neuromuscular performance variables (p > .05; gav = 0.00-0.27). Red urine production was the only side effect, demonstrating a significantly higher prevalence (p = .046) with beetroot juice ingestion. Three days of beetroot juice supplementation may be a useful nutritional strategy in semi-professional, male handball players given its ergogenic benefit to some aspects of neuromuscular performance.
Keywords: inorganic nitrate; nitric oxide; nutrition; power; strength; team sport.