Short-term citrulline malate supplementation enhances lower-limb function in physically active older women: A pilot randomized controlled trial.

PURPOSE: This pilot randomized controlled trial examined whether short-term (6-week) citrulline malate (CM) supplementation combined with multicomponent exercise could improve physical function, metabolic biomarkers, and quality of life in physically active older women.

METHODS

Twenty community-dwelling women aged 60-75 years were randomized to a 6-week exercise program (3 sessions/week) plus 3 g/day CM (n = 10) or placebo (n = 10). Outcomes were assessed pre- and post-intervention and included physical performance (sit-to-stand test, 6-min walk test [6MWT], Short Physical Performance Battery [SPPB]), blood biomarkers (25-hydroxyvitamin D [25(OH)D], cortisol, testosterone, creatine kinase, glucose), and quality of life (WHOQOL-BREF).

RESULTS

The CM group showed significant improvement in sit-to-stand performance (Δ = -1.62 ± 1.49 s; p = 0.023; d = 1.38). Trends towards greater improvements were observed in 6MWT distance (+61.0 ± 80.2 m vs. +15.8 ± 28.9 m; d = 0.65) and SPPB score (+0.60 ± 0.55 vs. -0.09 ± 0.70; d = 1.05) compared with placebo, although between-group differences were not statistically significant. Serum 25(OH)D increased with CM (+3.82 ± 5.01 ng/mL) and decreased with placebo (-0.90 ± 4.71 ng/mL). No significant between-group differences were observed in other biomarkers or quality-of-life domains. No adverse events were reported during the intervention.

CONCLUSIONS

Six weeks of CM supplementation combined with multicomponent training was associated with improved sit-to-stand performance in older women, with additional favourable trends in walking endurance, SPPB score, and 25(OH)D. Given the pilot nature of the study, these findings should be considered preliminary and hypothesis-generating. Larger and longer trials are needed to confirm the reproducibility, clinical significance, and potential mechanisms of these effects.