Acute Effects of Beetroot Supplementation on Resistance Exercise Performance in Physically Active Men

The objective of this study was to investigate the effect of nitrate (NO₃^-) supplementation on exercise performance in multiple sets of bench press (BP) and leg press (LP) at 80% of one-repetition maximum (1RM), to determine whether it would be beneficial towards the number of repetitions to failure (RTF). A total of 18 trained male subjects (25 ± 3 years old) completed two sessions of repeated number of maximum repetition (NMR) tests in BP and LP to assess RTF, power output, heart rate (HR), rating of perceived exertion (RPE) 2 h after NO₃^- or placebo intake. Comparisons between dependent variables were conducted using a two-factor analysis of variance (ANOVA) with repeated measures, examining the factors of condition and sets. The results for RTF showed only a main effect of set for BP and LP. No significant differences were found between conditions for total RTF. Our results showed that the NO₃^- supplementation had no significant effect on RTF, mean power, peak power, HR, and RPE when compared to placebo conditions. Results demonstrated that for physically active male individuals with experience in strength training, NO₃^- supplementation did not affect strength endurance performance.