Dietetics · Aug 1, 2025

Branched-Chain Amino Acids Combined with Exercise Improves Physical Function and Quality of Life in Older Adults: Results from a Pilot Randomized Controlled Trial

By Robbins R, O'Connor JC, Cortes TM et al.

This pilot, randomized, double-blind, placebo-controlled trial investigated the effects of branched-chain amino acids (BCAAs)-provided in a 2:1:1 ratio of leucine:isoleucine: valine-combined with exercise on fatigue, physical performance, and quality of life in older adults. Twenty participants (63% female; BMI: 35 ± 2 kg/m²; age: 70.5 ± 1.2 years) were randomized to 8 weeks of either exercise + BCAAs (100 mg/kg body weight/d) or exercise + placebo. The program included moderate aerobic and resistance training three times weekly. Physical function was assessed using handgrip strength, chair stands, gait speed, VO₂ max, and a 400 m walk. Psychological health was evaluated using the CES-D, Fatigue Assessment Scale (FAS), Insomnia Severity Index (ISI), and global pain, fatigue, and quality of life using a visual analog scale (VAS). Significant group x time interactions were found for handgrip strength (p = 0.03), chair stands (p < 0.01), and 400 m walk time (p < 0.01). Compared to exercise + placebo, exercise + BCAAs showed greater improvements in strength, mobility, and endurance, along with reductions in fatigue (-45% vs. +92%) and depressive symptoms (-29% vs. +5%). Time effects were also observed for ISI (-30%), FAS (-21%), and VAS quality of life (16%) following exercise + BCAA supplementation. These preliminary results suggest that BCAAs combined with exercise may be an effective way to improve physical performance and reduce fatigue and depressive symptoms in older adults.

doi.org/10.3390/dietetics4030032 Open access PubMed 40860958 Interventions