Protein for training: how much, and when

The International Society of Sports Nutrition (ISSN) position stand on protein and exercise concludes that an overall daily intake of 1.4 to 2.0 g of protein per kilogram of body weight is sufficient for most exercising people, both for building muscle and for keeping it.

For example, someone who weighs 70 kg would be looking at roughly 98 to 140 g of protein a day. The same position stand notes that resistance-trained people eating fewer calories than they burn may need more (2.3 to 3.1 g/kg/day) to hold on to muscle while losing weight.

The ISSN’s general recommendation for each serving is 0.25 g of high-quality protein per kilogram of body weight, or a dose of 20 to 40 g, ideally spread evenly every 3 to 4 hours across the day rather than eaten in one or two large meals.

Timing around training matters less than people often think: the position stand finds benefits from eating protein either before or after a workout, and notes that the effect of exercise on muscle lasts at least 24 hours. Getting enough across the day comes first.

Whole foods can cover your needs: the ISSN says physically active people can get their daily protein from food, with supplements a practical option when it is hard to get enough. The NHS describes meat as a good source of protein, and lists fish, eggs, beans and pulses as other sources.

The NHS Eatwell Guide advises choosing lean meat and eating less red and processed meat, and aiming for at least two portions of fish a week (2 × 140 g), one of them oily. If you eat more than 90 g of red or processed meat a day, the NHS recommends cutting down to 70 g.