Muscle mass index showed no significant gain in an exercise and supplement trial
Healthy older adults received the same amino acid supplement with different exercise routines. Walking speed improved in both groups, without a detected difference between them.
Based on the published abstract. The full paper may contain additional methods, results and limitations.
The 30-second takeaway
Neither exercise group showed a statistically significant rise in the measured limb muscle mass index. Walking speed improved in both groups, with no detected difference between routines. Because everyone received the amino acid supplement, the trial cannot isolate its contribution. These results leave uncertainty about whether supplementation itself improves muscle mass or function.
Both groups received supplements, so there was no unsupplemented comparison. Participants and researchers were aware of the assigned routines. The abstract provides no effect sizes or confidence intervals to show the range of effects compatible with the findings.
What researchers found
Gait speed
At 6 months, walking speed improved in both the resistance training and regular walking and strengthening groups, each receiving the same supplement.
What the comparison tests
Researchers compared resistance training with regular walking and strengthening exercises. Since both groups took the same daily supplement after exercise, this design primarily compares exercise routines in people receiving supplementation.
Other outcomes were limited
Grip strength improved only in the control group's nondominant hand, leaving a limited finding to interpret. No serious adverse events were reported, and kidney function stayed stable during the trial.
The original publication
Effect of leucine-enriched essential amino acid supplementation combined with different exercise regimen on appendicular skeletal muscle mass and muscle performance in older adults: an open label randomized controlled trial.
Thavonlun C, Limsapjaroen J, Yoosuk P et al.
JBMR Plus · 2026
- PubMed ID
- 42038818
- Record checked
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