For lifting, total daily protein matters more than timing; benefit levels off around 1.6 g/kg/day, and older muscle needs more protein per meal for the same short-term response
Interpretation
Morton et al.'s meta-analysis of 49 RCTs (1,863 healthy adults) found protein supplementation modestly increased strength and fat-free mass gains from resistance training, with no further gain above about 1.62 g/kg/day and a smaller benefit with age. The ISSN position stand places timing as a matter of tolerance. Moore et al.'s laboratory analysis in men found older men's protein synthesis plateaued at a higher relative dose per meal (0.40 vs 0.24 g/kg, p = 0.055; clearer per kg lean mass), and Doering et al.'s review concluded that training reduces but doesn't eliminate anabolic resistance in masters endurance athletes. But in 8 masters triathletes, doubling post-exercise protein didn't significantly improve recovery or next-session performance. Graded moderate: the meta-analysis is large but in resistance-only trainees, the age evidence is acute laboratory data in men, and the only triathlete study is tiny.
Practical implication
Lifting triathletes, especially over 50, can focus on adequate total protein spread across meals rather than precise timing, while keeping carbohydrate the priority for endurance training. The g/kg figures are research findings, not individual targets; no trial has tested long-term protein needs in masters triathletes who lift, and people with kidney disease need medical advice before increasing protein.
Sources
5 sources, independently verified.
In 49 RCTs of at least 6 weeks of resistance training, protein supplementation added 2.49 kg to 1RM strength (95% CI 0.64 to 4.33) and 0.30 kg fat-free mass (0.09 to 0.52). Total protein intakes above about 1.62 g/kg/day produced no further fat-free mass gain. The benefit was smaller with older age and larger in resistance-trained people. Healthy adults doing resistance training, not endurance athletes.
Retrospective laboratory analysis: muscle protein synthesis plateaued at about 0.40 g/kg body mass per dose in older men vs 0.24 g/kg in young men (p = 0.055), and 0.60 vs 0.25 g/kg lean body mass (p < 0.01). Basal synthesis was similar. Men only; short-term acute response, not long-term muscle gain.
Position stand for healthy exercising people: about 1.4-2.0 g/kg/day is sufficient for most; doses of about 0.25 g/kg or 20-40 g spread every 3-4 hours; timing largely a matter of tolerance, with the anabolic effect of exercise lasting at least 24 hours; whole foods can meet needs; endurance athletes should prioritise carbohydrate.
Review: masters endurance athletes recover more slowly than younger athletes after muscle-damaging exercise but not after non-damaging exercise; training reduces but does not eliminate anabolic resistance; masters athletes are usually advised about 20 g or 0.25 g/kg post-exercise and might benefit from more, but no specific figure is given.
Randomised double-blind crossover: after a 30-minute downhill run, 0.6 g/kg vs 0.3 g/kg protein per feeding (three feedings, every 2 hours) did not significantly change recovery between conditions; an 8-hour-later cycling time trial was 2,395 vs 2,369 s (d 0.09). Strength loss (-3.6% vs -8.6%) and fatigue were within-condition effects only. Very small sample.