According to a review published in Frontiers in Nutrition, drinking a casein protein before sleep can increase gains in muscle mass and strength, and protein calories consumed before bed does not increase body fat. These findings suggest that sleep is a unique window for boosting muscle gains.
“Several one-night studies have shown that pre-sleep protein intake increases muscle protein synthesis during overnight sleep in young adults” says lead author Dr. Tim Snijders, Assistant Professor at Maastricht University, who conducted the most compelling study to support these findings to date.
Dr. Tim Snijders studied 44 healthy young men over aon a 12-week lifting program. Half of the men were given a protein shake before sleep with about 30g of casein and 15 grams of carbs. After the 12 weeks both groups had improved their squat (one rep max) and had bigger quads, but the group that consumed the protein shake before bed had significantly more muscle strength and size.