Creatine plus lifting adds 11.35 kg to lower-body strength, in men at least

Creatine is among the most researched supplements in sport, and plenty of pooled analyses have already concluded it helps strength. What most of them skipped is whether the answer changes with the lifter's age, sex, training duration or dose. This review set out to pool the trials in adults under 50 specifically, and to test whether those confounding variables alter how much strength creatine actually adds on top of resistance training. For anyone lifting weights and weighing up the supplement, that is the practical question: not whether creatine works in general, but for whom and by how much.

The authors searched four databases, MEDLINE, Scopus, Embase and SPORTDiscus, up to 22 May 2024 for trials that combined creatine supplementation with resistance training and compared it against a placebo. Twenty-three studies met the criteria. Twenty involved men, contributing 447 male participants, while just 2 studies involved women, with 40 female participants, and 1 further study mixed the sexes with 13 men and 9 women. The team pooled changes in upper-body and lower-body strength, then ran subgroup analyses to check whether sex, dose or other variables shifted the outcome.

Compared with placebo, creatine plus resistance training increased upper-body strength by a weighted average of 4.43 kg and lower-body strength by 11.35 kg. Men taking creatine gained significantly in both upper- and lower-body strength, whereas women showed no significant gains, and there was a trend towards larger upper-body improvements in men than in women. A second trend suggested high-dose creatine might deliver greater lower-body gains than lower doses, though neither trend reached statistical significance. No other variable the authors examined changed the size of creatine's effect.

The headline result confirms what earlier pooled analyses have repeatedly found: adding creatine to resistance training reliably beats training with a placebo for strength. Where this review adds something is the breakdown by sex and dose in under-50s, and there it complicates the story, because the female evidence is extremely thin, resting on a small number of participants across very few trials. That means no significant benefit in women could reflect a genuine sex difference or simply a shortage of data. One author also reports ties to creatine manufacturers, which readers should weigh. Larger trials in women are the obvious next step.

If you are under 50 and lift weights, this is a further reason to think creatine can add meaningful kilograms to your lifts beyond what training alone delivers. Men have the strongest grounds for that expectation, since nearly all the pooled participants were male and their gains were clear and consistent. Women should not necessarily conclude creatine does nothing for them; the honest reading is that the question has barely been tested. The hint that higher doses help lower-body strength more is preliminary and did not reach significance, so treat it as a curiosity rather than a conclusion.