Two October papers on creatine in older adults point at strength, not muscle mass

Creatine has spent the past two years being repositioned. Long marketed to young men trying to add mass, it is increasingly discussed as a countermeasure to sarcopenia — the age-related loss of muscle and strength that drives a large share of falls, frailty and loss of independence. Two papers published within 48 hours of each other in October test different parts of that claim [s1][s2].

Read together, they point in a consistent and slightly awkward direction: the measurable benefit in older adults shows up in strength and function, and much less clearly in the tissue.

The meta-analysis

The larger of the two pooled trials comparing creatine plus exercise training against placebo plus exercise training in older adults [s1]. Scopus, Web of Science and PubMed were searched, with database access on 30 August 2024; twenty articles met the inclusion criteria, covering 1,093 participants, 69% of them female [s1]. The protocol was registered in PROSPERO (CRD42024581817) and study quality was assessed with the PEDro scale [s1].

Three outcomes were reported:

• One-repetition maximum improved significantly, with a mean difference of 2.122 kg (Z = 3.255, P = 0.001) [s1].
• Fat percentage fell significantly, with a mean difference of −0.548% (Z = −2.231, P = 0.026) [s1].
• Total body bone mineral density did not change, with a mean difference of 0.009 g/cm² (Z = 0.587, P = 0.557) [s1].

The authors conclude that older adults participating in exercise training with creatine supplementation can improve functional performance and body composition, while noting that the bone density effect requires further study [s1].

Two kilograms on a one-rep max is a real but small effect, and it is worth keeping the comparator in view. Both arms trained. This is not the difference between supplementing and doing nothing; it is the increment creatine adds on top of resistance training, which is doing the heavy lifting in both groups.

The crossover trial

The second paper is a randomised, double-blind, placebo-controlled crossover trial of creatine monohydrate combined with β-hydroxy-β-methylbutyrate (HMB) [s2]. Thirty physically active older adults — 20 men and 10 women, all aged 60 or over — completed two six-week intervention periods separated by a three-week washout [s2].

Both periods included the same integral physical conditioning programme: four supervised sessions per week combining strength, power, multicomponent circuits, high-intensity interval and moderate-intensity continuous training, performed at 40–100% of training heart rate and 20–90% of one-repetition maximum [s2].

Body composition was assessed by bioelectrical impedance. Significant time × group interactions appeared for fat mass, fat-free mass, total muscle mass, skeletal muscle mass, appendicular skeletal muscle mass, muscle mass index, skeletal muscle index and appendicular lean mass over BMI, all at p < 0.05 [s2]. But the authors are explicit that the within-group changes were not statistically significant — the creatine-plus-HMB condition showed reductions in fat mass and body fat percentage with only slight numerical increases in muscle parameters, while placebo trended the other way [s2].

What did move was function. Creatine plus HMB significantly improved leg and back strength, arm flexion strength, upper-body endurance measured by dumbbell flexion, push-ups and an isometric hold, and core endurance measured by crunches [s2]. Regression analyses suggested these improvements were largely independent of changes in muscle mass, which the authors interpret as pointing to a neuromuscular mechanism [s2].

Why the mass-versus-function split matters

Sarcopenia is usually explained to the public as muscle loss, and interventions are usually sold on muscle gain. Both of these papers found the clearer signal somewhere else — in what the muscle could do rather than how much of it there was.

That is not a paradox. Force production depends on neural drive, motor unit recruitment and rate coding as much as on cross-sectional area, and creatine's best-established mechanism — expanding the phosphocreatine pool available for rapid ATP resynthesis — acts on the ability to sustain high-intensity efforts rather than on protein accretion directly. In older adults, where neural factors account for a large share of strength loss, a function-first effect is mechanistically reasonable.

It also has a practical consequence for interpretation: a study that only measures lean mass by impedance may miss the effect entirely, and a study that only measures strength cannot say whether tissue changed.

What neither study establishes

Neither paper is large. Thirty participants in a crossover trial [s2] and 1,093 pooled across 20 heterogeneous trials [s1] are modest evidence bases for a claim about healthy ageing.

The crossover design in the second study carries a specific risk: with a training programme running through both periods, a three-week washout may not be enough to erase the training adaptation from the first block, which can bias a crossover comparison depending on order [s2]. The paper reports the design; readers should weight the order effect accordingly.

The meta-analysis pools trials that differed in dose, duration and training programme, which is the standard limitation of supplement meta-analyses and the reason a single pooled mean difference should be read as an average of dissimilar things [s1].

Neither study measured falls, fractures, disability or independence. Bone mineral density, the outcome closest to fracture risk, was the one outcome that did not move [s1].

What to watch

The open question is durability. Six weeks and the typical trial lengths inside a meta-analysis tell you about acute adaptation, not about whether a strength increment holds across years and translates into fewer falls. Trials with clinical endpoints in older adults, rather than performance endpoints, are what would move this from a plausible countermeasure to an established one.

This article describes research findings and is not medical advice. Decisions about supplementation in older adults involve kidney function, medication interactions and individual circumstances that no trial average addresses.

Sources

• [s1] Impact of creatine supplementation and exercise training in older adults: a systematic review and meta-analysis — European Review of Aging and Physical Activity, published online 8 October 2025. https://doi.org/10.1186/s11556-025-00384-9
• [s2] Combined creatine and HMB co-supplementation improves functional strength independent of muscle mass in physically active older adults: a randomized crossover trial — GeroScience, published online 10 October 2025. https://doi.org/10.1007/s11357-025-01889-y