A study by health and exercise scientists at the University of Stirling is challenging the perception that men with more muscles mass need more protein after resistance exercise to promote muscle growth.
The scientists found no difference in muscle growth after protein between smaller and bigger participants.
Irrespective of the participant’s size, muscle growth and recovery was higher and faster after larger amounts of protein were consumed. The scientists found consuming 40 grams of protein after exercise, instead of 20, promoted increased muscle growth.
Kevin Tipton, Professor of Sport, Health and Exercise, at the University of Stirling said: “There is a widely-held assumption that larger athletes need more protein, with nutrition recommendations often given in direct relation to body mass.
“In our study, participants completed a bout of whole-body resistance exercise, where earlier studies – on which protein recommendations are based – examined the response to leg-only exercise.
“This difference suggests the amount of muscle worked in a single session has a bigger impact on the amount of protein needed afterwards, than the amount of muscle in the body.”

According to Tipton, both the American College of Sports Medicine and the British Nutrition Foundation held the belief an individual does not need more than 25 grams of protein after exercise to maximally boost muscle growth.
Tipton added: “In order for nutritionists to recommend the correct amount of protein we first need to consider specific demands of the workout, regardless of athletes’ size. This throws commonly held recommendations into question and suggests the amount of protein our muscles need after exercise may be dependent on the type of workout performed.
“These results are limited to younger, trained men so we may see different results with other groups, such as older individuals or females digesting different amounts of protein.”
For the study, the scientists recruited young, resistance-trained males. They divided them into two groups according to weight and invited them to trials in which they consumed protein after exercise.
In the first one they consumed 20 grams, and in the second, 40 grams of whey protein. They then measured the muscle’s ability to grow at an accelerated rate.