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.
The whole scare traces to one 2009 study that measured a hormone, not hair. In 2025, the first trial to actually assess hair follicles found no difference between creatine and placebo.
For most people eating normally, added electrolytes do little, and plain water rehydrates fine for ordinary exercise. The clearest endurance danger is drinking too much — and the proven use is illness, not the gym.
An umbrella review of 21 meta-analyses found caffeine helps endurance, strength, power and sprinting. The effect is real but modest, and the useful dose is smaller than many gym pre-workouts pack in.
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.
For everyday exercise, food and water replace what sweat takes. The dangerous salt problem in endurance events is usually too much fluid, not too little sodium — and extra salt does not prevent it.
Pooled trials show a small boost to oxygen uptake and exercise tolerance from dietary nitrate. The effect shrinks toward zero in the most trained athletes.
The same audit found high-performance female athletes well represented in the field — and that the studies generating prevalence figures lean on self-reported food records and MET lookup tables.
A tightly controlled crossover trial separated low energy availability from low carbohydrate availability for four days. One hormone moved clearly; most did not, and performance did not move at all.