Combined creatine and β-hydroxy-β-methylbutyrate supplementation with integral conditioning exercise enhances functional performance and metabolic health in physically active older adults: A randomized controlled crossover trial

Combined creatine monohydrate (CRE) and β-hydroxy-β-methylbutyrate (HMB) supplementation may counteract age-related declines in functional capacity, yet evidence in physically active older adults is scarce. To investigate the effects of six weeks of CRE + HMB supplementation integrated with a supervised multicomponent exercise program on functional performance, metabolic efficiency, and physiological health in older adults. Thirty physically active adults aged ≥ 60 years (20 men, 10 women) completed a randomized, double-blind, placebo-controlled crossover trial involving two 6-week intervention phases (CRE + HMB or placebo), separated by a 3-week washout. The exercise program (4 sessions/week) combined strength, endurance, and coordination training. Functional tests (4-m gait speed, 5-repetition sit-to-stand, Timed Up and Go, 400-m walk), metabolic indices, and cardiopulmonary and inflammatory markers were assessed pre- and post-intervention. CRE + HMB significantly improved gait speed, sit-to-stand, TUG, and 400-m walk (p < 0.05), with large effect sizes (η²p = 0.15–0.29). Basal metabolic rate and metabolic rate index increased, while visceral adiposity showed favorable trends. Women exhibited reductions in diastolic blood pressure and higher expiratory strength; men showed a transient rise in endothelial protein C receptor (EPCR). No period, sequence, or carryover effects were detected. Six weeks of CRE + HMB supplementation integrated with supervised multicomponent training enhanced mobility, metabolic efficiency, and selected physiological outcomes in physically active older adults. This strategy represents a safe, feasible, and practical approach to sustain functional independence and metabolic health with aging.