Effects of Coenzyme Q10 Supplementation on Physical Function Adaptations to High-Intensity Interval Training in Older Adults

Objectives: This study investigated whether CoQ10 supplementation enhances physical adaptations to high-intensity interval training (HIIT) in muscular strength, power, and physical function in older adults. Method: In a double-blind, randomized controlled trial, 38 adults aged 65–75 were assigned to either a CoQ10 (Females: 8; Males: 11) or placebo (Females: 8; Males: 11) group and completed an 8-week supervised HIIT program. Lower- and upper-body strength (30s 5-repetition chair stand 5XSST, chair standing 30CST, handgrip strength HGR/L), balance (single-leg stand SLS, timed up and go TUG), mobility (25-foot walk 25FW), and aerobic endurance (6-minute walk 6MWT) were assessed pre- and post-intervention. Results: The CoQ10 group demonstrated significantly greater improvements in 5XSST and 30CST compared to the placebo group (p 0.05). No adverse events were reported. Conclusion: While CoQ10 supplementation enhanced improvements in lower-body strength and power, as indicated by the greater gains in 5XSST and 30CST performance compared to the placebo, no between-group differences were observed in TUG, grip strength, or other functional outcomes. This suggests that the performance-related effects of CoQ10 may be more specific to muscular power output and fatigue resistance, rather than general mobility or balance-related tasks. These findings highlight the potential of CoQ10 as a targeted adjunct in exercise for supporting lower-body function and physical performance in older adults.