Hitting the weight room is only one aspect of the muscle building process. You also have to take rest and nutrition into consideration. A study recently published in The Journal of Nutrition helps illustrate nutrition’s importance for maintaining and building lean mass.

Twenty-four healthy older men were given a drink containing 21 grams of leucine-enriched whey protein, 9 grams of carbohydrates, 3 grams of fat and 800 IU vitamin D each morning before breakfast for 6 weeks. Some received a placebo.

Rates of protein synthesis were higher for subjects receiving the whey and vitamin D supplement compared to those who got the placebo. The supplemented group also gained more lean mass.