Study
Effect of creatine supplementation during resistance training on lean tissue mass and muscular strength in older adults: a meta-analysis
Across 22 RCTs and 721 older adults, adding creatine to resistance training produced 1.37 kg more lean tissue mass than training alone (95% CI 0.97 to 1.76 kg, p < 0.00001).
Philip Chilibeck and colleagues pooled 22 RCTs covering 721 men and women. Study mean ages ran from 57 to 70 years. Every trial paired supplementation with resistance training performed 2 to 3 days per week. Trial length ran from 7 to 52 weeks. Eight trials used a loading phase of 20 g/day for 5 to 7 days; maintenance doses were typically 3 to 5 g/day, with weight-based arms at 0.1 to 0.3 g/kg/day.
Three outcomes were pooled. Lean tissue mass: mean difference 1.37 kg, 95% CI 0.97 to 1.76 kg, p < 0.00001. Chest press strength: SMD = 0.35, 95% CI 0.16 to 0.53, p = 0.0002. Leg press strength: SMD = 0.24, 95% CI 0.05 to 0.43, p = 0.01.
The result held after removing trials that combined creatine with protein or other supplements (lean mass 1.44 kg) and after removing trials in people with chronic disease (lean mass 1.26 kg). Funnel plots showed no publication bias. On safety, four trials reported gastrointestinal events and two reported muscle cramping, none causing withdrawal. Five trials lasting 3 to 52 weeks tested liver or kidney markers and found no adverse effects.
In summary, creatine supplementation increases lean tissue mass and upper and lower body muscular strength during resistance training of older adults, but potential mechanisms by which creatine exerts these positive effects have yet to be evaluated extensively.
The authors state that only just over half of the individual trials showed a significant effect, so the pooled result depends on aggregation. Jadad quality scores ranged from 2 to 5 out of 5. Five of 22 trials bundled creatine with protein, whey, leucine, vitamin D, conjugated linoleic acid or L-carnitine, which confounds attribution in those arms. Seven trials enrolled people with coronary artery disease, heart failure, Parkinson's disease, COPD, type 2 diabetes or osteoarthritis rather than healthy older adults. The authors state the roughly 700-participant pool may be underpowered to detect adverse events. Lean mass was measured by three different methods (DXA, hydrostatic weighing, air displacement plethysmography). No effect is claimed without resistance training. Darren Candow and Philip Chilibeck publish extensively on creatine; the paper declares no conflicts of interest, and no funding statement was available on the page.
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