Beetroot juice or creatine: which yields greater short-term benefits for resistance training capacity, performance and key physiological responses?

This randomized controlled crossover trial compared the short-term effects of creatine (CR) and beetroot juice (BJ) on resistance training performance and physiological responses across ∼72 h supplementation period. Eleven novice resistance-trained men completed bench press (BP) and back squat (BS) sets at 60-80% 1RM under CR, BJ, and placebo (PLA) conditions. Performance outcomes, intramuscular-oxygen-saturation (SmO₂), peak heart rate (HR), and heart rate variability (HRV) were assessed. Individual modulation prevalence was also determined. CR significantly improved repetition performance at 80% 1RM in BP (<i>d</i> = 1.33) compared to PLA. Both CR and BJ produced moderate-to-very large effects on velocity with superior effect using BJ (<i>d</i> = 1.40-2.82 vs. PLA). Higher SmO₂ (<i>d</i> = 1.74-2.9), lower peak HR (<i>d</i> = 0.83-2.74), and more favourable autonomic recovery (e.g. RMSSD: <i>d</i> = 0.91-2.99) were observed with BJ compared to both PLA and CR. Modulation analysis indicated greater proportions of meaningful individual adaptations, following BJ compared to CR. Overall, CR appeared to preferentially enhance mechanical performance, whereas BJ seemed to provide broader cardiometabolic and autonomic benefits.