For how we live.
The muscle-building literature converges on roughly 1.6 grams of protein per kilogram of bodyweight a day, with gains flattening above that — a target well clear of the deficiency floor most official figures quote.
No. When sets are pushed close to failure, light and heavy weights build muscle about equally. The one thing heavier loads reliably win is maximal strength.
Failing mitochondria are one of ageing's core hallmarks, and human trials of mitochondria-targeted compounds show flickers of benefit — but the strongest endpoints keep coming back null.
Even frail people in their 80s and 90s roughly doubled their strength in ten weeks of training. But muscle size barely moved — the honest expectation is a big gain in function and a modest one on the scale.
Mouse studies claimed one circulating protein reversed ageing of the heart, muscle and brain. A second team found the muscle effect ran the opposite way — and no human trial has ever tested it.
Weekly scans found thigh muscle grew measurably within about three to four weeks, once early swelling was discounted. A biopsy study found real fibre growth appeared only later, at ten weeks.
Branched-chain amino acids can nudge muscle protein synthesis and modestly ease soreness, but they cannot build muscle on their own — and a complete protein does everything they do and more.
In 2,292 older adults, weak quadriceps tracked with higher mortality — but muscle size, measured by CT and DXA, did not. The finding reshaped how sarcopenia is defined and moved the target from bulk to strength.
Sore muscles signal unaccustomed or eccentric effort, not how much you gained. In one 10-week study, peak muscle damage was unrelated to hypertrophy; growth tracked the later, calmer weeks.
A kilogram of muscle burns about 13 calories a day at rest — far less than the fitness-marketing figure implies. But resistance training does nudge resting metabolism up, by roughly 96 calories a day in a meta-analysis.
The familiar explanation — dehydration and lost salts — is the weakest part of the evidence. The better-supported idea is that cramping is a failure of nerve control, which is why a mouthful of pickle juice can stop one.
Frailty has firm diagnostic criteria and predicts falls, hospital stays and death. It is also, unusually, treatable: resistance training raised muscle strength 113% even in nursing-home residents in their late 80s.
A transcriptomic sub-study of the CALERIE calorie-restriction trial links 151 genes to preserved leg strength during weight loss, independent of how much body mass was lost.
The training and creatine at its core rest on strong evidence. The supplement stack around them mostly doesn't — and the SARMs some users add are frequently not even the drug on the label.
In half a million people, weaker grip tracked with higher mortality — a strong marker. But it reads out whole-body strength and health, not a number you move by training your hands.
A large trial in adults up to 89 found structured activity cut the risk of losing the ability to walk. In frail nursing-home residents near 90, strength training more than doubled muscle strength.
Sarcopenia got a formal definition and diagnostic cut-offs. The clinical guidelines that followed back resistance exercise strongly — and are far more cautious about protein powders, vitamin D and drugs.
A 2026 meta-analysis pooled every randomised human trial of the gut-derived supplement for muscle health. Only one outcome, from two trials, could be combined — and it missed significance.