What the research found

Protein supplementation alone does not preserve muscle mass or strength in ageing adults. A two-year trial in women over 70 who consumed a protein shake daily showed muscle decline matching a placebo group. Meta-analyses pooling over 1,600 older adults reached the same conclusion: additional protein without accompanying stimulus produced no protective effect against age-related muscle loss.

Resistance training, by contrast, did build muscle and strength in postmenopausal women. The key distinction is that protein appears necessary only in the context of mechanical loading—adding extra protein on top of a resistance programme provided no additional benefit beyond what training alone achieved. The implication is that protein acts as a substrate for adaptation when a training signal is present, but cannot substitute for that signal.

Why it matters for you

If you're over 50 and tracking protein intake in the app, the takeaway is practical: meeting your baseline protein requirement matters, but scaling consumption beyond that without concurrent strength training is unlikely to move your muscle biomarkers. Your effort is better invested in the resistance protocol itself.

For users designing periodised training, this reframes protein as a supporting factor rather than a limiting one. You still need adequate intake during phases where you're intentionally building or maintaining muscle—particularly during caloric restriction, where protein requirements do rise. But the stimulus hierarchy is clear: load > protein. Measuring lean mass via DEXA or tracking strength metrics (compound lifts, grip strength) will tell you whether your current protein intake is sufficient; static consumption of higher amounts won't predict better outcomes without the training component.

The timing question also simplifies your protocol: nutrient timing around workouts does not appear to matter for the outcome most users care about.

Caveats

• Much of the evidence comes from observational or quasi-experimental designs; large randomised controlled trials directly comparing protein doses in trained versus untrained older adults are limited
• The research primarily addresses maintenance and modest gains; higher protein may still support aggressive hypertrophy protocols in younger or elite populations
• Individual variation in protein turnover and hormonal status (e.g. oestrogen loss, testosterone levels) is not detailed in the summary
• The studies referenced do not appear to control for confounders like overall dietary quality or adherence differences between groups