Citrulline Malate Boosts Physical Function in Active Older Women
A pilot RCT tests whether 3g daily citrulline malate improves mobility, strength, and biomarkers in women over 65 doing multicomponent training.
Summary
This small randomised controlled pilot trial enrolled 33 community-dwelling women aged 65 and older, assigning them to a structured multicomponent exercise programme three days per week combined with either 3 grams per day of citrulline malate or a placebo. Researchers assessed physical performance using the six-minute walk test, sit-to-stand test, and the Short Physical Performance Battery, while also tracking blood biomarkers including vitamin D, glucose, creatine kinase, and hormones, alongside self-reported quality of life. The study aimed to evaluate whether citrulline malate supplementation could amplify the benefits of exercise training in older women, a population at heightened risk of sarcopenia and functional decline. Results from this completed trial offer early signals on the supplement's potential role in healthy ageing protocols.
Detailed Summary
Maintaining physical function in older adults is one of the most urgent challenges in longevity medicine. Muscle weakness and reduced mobility are leading predictors of frailty, falls, and loss of independence. Citrulline malate, an amino acid compound known to enhance nitric oxide production and reduce exercise-related fatigue, has shown promise in younger athletic populations, but its effects in older adults are far less studied.
This pilot randomised, double-blind, placebo-controlled trial recruited 33 community-dwelling women aged 65 or over from the Universidad de Burgos in Spain. Participants followed a supervised multicomponent training programme three times per week and were randomised to receive either 3 grams of citrulline malate daily or a matched placebo. The two-month intervention (March to May 2020) captured both functional and biochemical outcomes.
Physical performance was evaluated through the six-minute walk test (6MWT), sit-to-stand test, and Short Physical Performance Battery (SPPB) — validated tools commonly used in clinical ageing research. Blood markers included vitamin D, fasting glucose, creatine kinase, and hormonal panels. Quality of life was measured using the WHOQOL-BREF questionnaire.
The abstract does not disclose quantitative results, limiting interpretation. However, the combination of exercise with citrulline malate targets a plausible mechanism: improved blood flow and reduced muscular fatigue could potentiate training adaptations in older muscles. If efficacy is confirmed, even modest functional gains in this population carry significant clinical and public health relevance.
Key caveats temper enthusiasm. The enrolled sample was small (20 participants completed the trial, down from 33 enrolled), the intervention period was only eight weeks, and the study was restricted to women, limiting generalisability. The Phase N/A designation and pilot scope mean findings are hypothesis-generating rather than definitive. Larger, longer trials across both sexes are needed before clinical recommendations can be made.
Key Findings
- 3g daily citrulline malate combined with exercise was tested for functional benefits in women aged 65+ over 8 weeks.
- Physical performance assessed via 6MWT, sit-to-stand, and SPPB — validated functional ageing measures.
- Blood biomarkers including vitamin D, glucose, creatine kinase, and hormones were tracked alongside function.
- Only 20 of 33 enrolled participants completed the trial, suggesting feasibility challenges in this pilot.
- The study provides early pilot-level data on citrulline malate as an adjunct to exercise in older women.
Methodology
Double-blind, placebo-controlled randomised pilot trial with 33 enrolled and 20 completers, running 8 weeks. Participants followed a multicomponent exercise programme three days per week alongside 3g daily citrulline malate or placebo. Outcomes included validated functional performance tests, blood biomarkers, and quality-of-life questionnaires.
Study Limitations
Summary is based on the abstract only; full results, statistical outcomes, and adverse event data are unavailable. The trial was a small pilot with only 20 completers, an exclusively female sample, and a brief 8-week duration, all of which limit generalisability and statistical power. Phase N/A classification confirms this is exploratory rather than definitive evidence.
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