The Effect of Beetroot Juice Supplementation Dose on Neuromuscular Performance During Resistance Exercise in Trained Males

The ergogenic effects of nitrate supplementation for enhancing resistance exercise performance, particularly in activities requiring high-power and high-velocity muscle contractions, remains unclear, and the optimal dose is unknown. PURPOSE: This study aimed to evaluate dose-dependent effects of nitrate on resistance exercise performance and descriptively explore potential interindividual variability in resistance-trained men. METHODS: Eighteen resistance-trained men participated in a randomized, double-blind, crossover trial involved four supplementation conditions: placebo (PL; negligible nitrate), low-dose nitrate-rich beetroot juice ( ~6.5 mmol nitrate), moderate-dose ( ~13 mmol nitrate), and high-dose (~26 mmol nitrate). Participants consumed supplements 2.5 hours before performing countermovement jumps (CMJ), back squat, and bench press exercises. Performance was measured using a linear transducer and force plate, assessed variables included power, velocity, and force. Individual performance changes were calculated as percentage differences from placebo and categorized into five color-coded groups ranging from highly positive (green) to highly negative (red) responses. RESULTS: No significant differences were found between supplementation conditions in peak power, velocity, jump height, or mean force during CMJ, back squats, or bench presses at either 50% or 75% of the one-rep maximum. (P>0.05). However, substantial intra- and interindividual variability was observed, as certain participants experienced small-to-large performance improvements under specific nitrate conditions, while others showed no beneficial effects. CONCLUSION: Nitrate supplementation had no significant effects on dose-dependent ergogenic effects overall, yet considerable individual variability suggests future research should further investigate factors influenced responsiveness to nitrate supplementation.