Short-Term Citrulline Supplementation Does Not Improve Functional Performance in Older Active Women

Abstract

Introduction: The aim of this study was to test the hypothesis that seven days of citrulline (CIT) supplementation would improve cardiovascular measures and functional performance in older active women. Methods:  Sixteen women (66.9±5.6yrs, 1.65±0.5m, 71.7±16.7kg) volunteered to participate in this randomized, double-blind, crossover-study. Participants underwent a series of functional fitness testing including a hand grip strength test, get-up and go, sit-to-stand, and a 6-minute walk test (6MWT). Heart rate and blood pressure (BP) were obtained at rest and following the 6MWT. Participants consumed 6g of citrulline or a placebo daily for seven days between pre- and post-testing in a counterbalanced fashion with a 14-day washout period between treatments. Data were analyzed via separate repeated measures analysis of variance. Results: A significant time by treatment interaction was observed for resting diastolic BP (F = 5.34; p = 0.028) indicating lower resting diastolic BP values following seven days of CIT supplementation compared to placebo. No other differences in cardiovascular measures were observed. There were no significant (p>0.05) differences between CIT and placebo for any measure of functional performance following the interventions. Conclusions: These results indicated that CIT did not influence functional performance, but CIT did improve resting diastolic blood pressure in older active female adults.