Creatine Plus HMB Boosts Strength in Older Adults Without Building More Muscle

Sarcopenia—the age-related loss of muscle mass and strength—is a leading cause of frailty, falls, and loss of independence in older adults. While resistance exercise is the gold-standard intervention, anabolic resistance in aging often blunts its effectiveness, making nutritional co-strategies critically important. This trial investigated whether combining two well-characterized supplements—creatine monohydrate (CRE) and beta-hydroxy-beta-methylbutyrate (HMB)—could amplify the benefits of a structured exercise program in physically active older adults.

Thirty participants (20 men, 10 women; mean age ~63 years) completed a randomized, double-blind, placebo-controlled crossover trial. Each underwent two 6-week intervention periods—one with CRE (3g/day) + HMB (3g/day) and one with an isocaloric inulin placebo—separated by a 3-week washout. Both periods included the same Integral Physical Conditioning (IPC) program: four supervised 60-minute weekly sessions combining strength, power, HIIT, moderate-intensity continuous training, and multicomponent circuits, performed at 40–100% training heart rate and 20–90% 1RM. Body composition was assessed via bioelectrical impedance analysis; functional strength was measured using leg/back dynamometry, handgrip, arm flexion, push-ups, isometric holds, and crunches.

Significant time-by-group interactions were observed across all major body composition indices (fat mass, fat-free mass, total and skeletal muscle mass, appendicular skeletal muscle mass, muscle mass index, skeletal muscle index, and ALM/BMI; all p<0.05). The CRE+HMB group showed numerical reductions in fat mass and slight increases in muscle parameters, while the placebo group trended in the opposite direction—but within-group changes did not reach statistical significance for body composition in either arm. In contrast, the CRE+HMB group achieved statistically significant improvements across multiple functional strength outcomes: leg/back strength, arm flexion strength, upper-body muscular endurance (dumbbell curls, push-ups, isometric holds), and core endurance (crunches).

Critically, regression analyses revealed that these functional strength gains were largely independent of changes in muscle mass, strongly implicating neuromuscular adaptations—such as improved motor unit recruitment, firing rate, and inter/intramuscular coordination—as the primary mechanism. This finding aligns with established evidence that early-phase strength gains in older adults are predominantly neural in origin. The complementary mechanisms of CRE (ATP resynthesis, mTOR activation, cell volumization) and HMB (anti-catabolic via ubiquitin-proteasome downregulation, mTOR anabolic signaling, membrane integrity) may synergistically enhance neuromuscular efficiency even within a short 6-week window.

Limitations include the relatively short intervention duration, reliance on bioelectrical impedance for body composition (less precise than DXA), a sample skewed toward physically active older adults (limiting generalizability to sedentary or frailer populations), and a modest sample size of 30. The absence of direct neuromuscular assessments (e.g., EMG) means the neural mechanism hypothesis, while well-supported by regression data, remains indirect. Nevertheless, this trial provides compelling evidence that CRE+HMB co-supplementation combined with structured multicomponent exercise represents a practical, accessible strategy to preserve functional capacity and promote healthy aging—even before measurable hypertrophy occurs.