Whey plus lifting tops the sarcopenia rankings

Ageing muscle loss — sarcopenia — erodes strength, mobility and independence, and both protein supplementation and exercise training are established countermeasures. What has been far less clear is which combination works best: there are many protein sources, from whey and casein to soy and milk, and several training modalities, from resistance to aerobic to multicomponent programmes. Individual trials rarely compare more than two options, so choosing between them has largely been a matter of preference and marketing. This analysis set out to rank the combinations against one another and to identify what moderates how well they work.

The authors searched MEDLINE Complete, PEDro, the Cochrane Library, Google Scholar, EMBASE and the China National Knowledge Infrastructure from inception to December 2025 for randomised controlled trials combining any protein supplementation with resistance, aerobic or multicomponent training in untrained older adults. In total 235 RCTs with 20,980 participants were included, spanning 10 identified protein sources and 24 monotherapy or combined regimens. A frequentist network meta-analysis with random-effects models produced standardised mean differences with 95% confidence intervals for lean mass, handgrip and leg strength, and physical mobility. Meta-regression tested participant and methodological moderators, and certainty of evidence was graded using GRADE.

Whey plus resistance training ranked as the most effective arm for muscle mass, with a large standardised mean difference of 1.29 at moderate certainty, and for leg strength, with a large SMD of 1.16, also at moderate certainty. Whey combined with multicomponent training performed best on functional measures: chair rise (SMD 1.09), timed up and go (SMD 0.70) and global mobility score (SMD 1.02), all at high certainty. The meta-regression indicated treatment efficacy was moderated by the participant's condition, the protein source and the protein dose, particularly for muscle mass and strength outcomes.

This consolidates a long-running assumption — that whey and resistance training are a strong pairing for older muscle — into a formal ranking built on an unusually large trial base. It also adds a useful nuance that a single-outcome study cannot: the best regimen depends on what you are trying to improve, with resistance work leading on mass and strength while multicomponent training leads on getting out of a chair and walking well. As with all network meta-analyses, many of these rankings come from indirect comparisons rather than head-to-head trials. Open questions include the optimal protein dose, whether the same hierarchy holds in already-trained older adults, and how durable the gains are.

If muscle size and leg strength are the goal in later life, this is strong reason to think whey alongside resistance training is the best-evidenced pairing available. If the priority is everyday function — rising from a chair, walking, turning — a mixed programme combining resistance with other modalities carried the strongest functional signal, and at high certainty. The trials recruited untrained older adults, so the size of these effects may not apply to someone already lifting regularly. Protein source and amount appeared to matter to the outcome, which is a reason to take both seriously rather than treating any protein as interchangeable.