Abstract
BACKGROUND: Inorganic nitrate (NO(3)(-)) may enhance muscle contractility and blood flow via nitric oxide production, offering potential ergogenic benefits. However, most studies have focused on males, and its effects in females during high-intensity, short-duration exercise remain unclear. OBJECTIVE: This review assessed the acute effects of nitrate supplementation on muscle strength, power, and sprint performance in healthy females. METHODS: A comprehensive literature search was conducted in PubMed, Web of Science, Scopus, SPORTDiscus, and Cochrane CENTRAL, from inception to July 2025. Randomized controlled trials (RCTs) that examined the effects of oral inorganic nitrate (e.g., beetroot juice or nitrate salts) in healthy females were included. Eligible studies involved (i) healthy women aged 18-30, (ii) nitrate supplementation vs. placebo, and (iii) outcome measures of muscle strength (e.g., MVC), power (e.g., countermovement jump height, peak power), or sprint performance (e.g., sprint time or repeated sprint ability). Studies were excluded if they did not report sex-specific results or lacked relevant physical performance outcomes. Random-effects meta-analyses were conducted for each outcome. RESULTS: Nitrate supplementation had small, non-significant effects on muscle strength (SMD = 0.10, 95% CI: -0.10 to 0.30, p > 0.05) and sprint performance (SMD = 0.14, 95% CI: -0.13 to 0.41, p > 0.05). A statistically significant, small-to-moderate improvement was observed in power (SMD = 0.38, 95% CI: 0.06 to 0.69, p < 0.05). Sensitivity analyses confirmed robustness of the power result. The certainty of evidence ranged from low to moderate based on the GRADE assessment. CONCLUSIONS: Inorganic nitrate supplementation may modestly enhance power in healthy females but does not appear to significantly improve muscle strength or sprint performance. These findings highlight the importance of sex-specific research in sports nutrition to guide targeted supplementation strategies for female athletes.