Timing protein before bed for gains

Consuming nutrients, primarily protein, during and around exercise to maximize training adaptations and facilitate repair and recovery has been a heavily investigated^[1] topic over the past several decades. This practice is a standard recommendation among sports nutrition authorities like the International Society of Sports Nutrition^[2] and American College of Sports Medicine^[3].

Nutrient timing strategies vary depending on the athlete and their goals, but the post-exercise period is generally considered to be of special importance due to the depletion of stored energy and damage to muscle fibers that occurs during exercise. Although a single exercise session^[4] increases muscle protein synthesis for up to 48 hours, overall muscle protein balance is negative without nutritional intervention. Consuming protein after training has been shown^[5] to shift muscle protein balance from a negative to a positive state, as depicted in Figure 1.

Figure 1: Pre-sleep protein feeding opportunity

Adapted from: Trommelen J & van Loon LJ. Nutrients. 2016 Nov.

However, the muscle-full effect^[6] proposes that protein ingestion stimulates muscle protein synthesis for only two to three hours, after which rates begin to decline, even when there is a continuous supply^[7] of amino acids. Accordingly, eating multiple meals after training appears necessary to maximize increases in muscle protein synthesis throughout the day. Yet, many people train in the evening after a full day of regular physical activity and food intake, eating only once or twice again before going to sleep and beginning an overnight fast.

Previous research^[8] has shown that supplementing with 40 grams of casein before bed results in significant elevations of muscle protein synthesis throughout the night. The study under review is a follow-up study that sought to determine whether a more moderate amount of protein would affect muscle protein synthesis rates.

Nutrient timing is a common and heavily investigated practice among athletes for maximizing training adaptations and facilitating repair and recovery. Consuming protein post-workout has been shown to stimulate muscle protein synthesis, but this effect only lasts for a couple hours, requiring further feeding for further stimulation. The study under review sought to evaluate whether consuming casein protein before sleep would augment overnight rates of muscle protein synthesis.