Acute and Chronic Effects of Dietary Nitrate Supplementation on Resistance Exercise Performance in Young Men: A Randomized, Triple-Blind, Placebo-Controlled Crossover Study

Although dietary nitrate supplementation has demonstrated ergogenic effects in endurance exercise, its efficacy in resistance exercise remains unclear. Therefore, this study examined the acute and chronic effects of dietary nitrate supplementation on upper-body resistance exercise performance. Eighteen resistance-trained men (age: 23.8 ± 3.2 years) completed a randomized, triple-blind, placebo-controlled crossover trial with four conditions: acute nitrate (1 day), chronic nitrate (7 days), acute placebo, and chronic placebo. During each session, participants performed five sets to failure at 70% 1RM in bench press and bench pull. No significant main effect of supplementation was observed for repetitions to failure, fastest velocity, or blood lactate concentration (p = 0.117–0.281). A significant supplementation × set interaction was detected for repetitions to failure (p = 0.006), with Bonferroni-adjusted pairwise differences observed only in Sets 1 and 4, but without a consistent pattern favoring nitrate supplementation. No significant differences were detected for any Multidimensional Fatigue Inventory subscale (p = 0.300–0.543). The omnibus test for Sleep quality was significant (p = 0.024), but post hoc comparisons did not reach statistical significance, although scores were numerically higher in the chronic nitrate condition than in both acute nitrate and acute placebo conditions (both p = 0.060). Taken together, the findings did not demonstrate a consistent performance benefit of acute or seven-day dietary nitrate supplementation during upper-body resistance exercise.