Defining the anabolic window of opportunity. Is protein intake immediately post resistance exercise critically important for muscle growth?

Abstract

The anabolic response of muscle to resistance exercise and protein feeding is influenced by multiple factors, including the timing of protein feeding. A common perception is that a 45-60 min post-exercise ‘anabolic window of opportunity' time frame exists, within which dietary protein must be consumed to achieve muscle anabolism (and ultimately muscle growth). In this review, we argue the importance of feeding protein immediately following exercise is not as critical as has been espoused. Indeed, muscle remains responsive to protein ingestion for at least 24 h post-exercise. On the other hand, given that feeding protein immediately post-exercise is unlikely to impair the muscle anabolic response, and could improve it, from a practical standpoint, we recommend athletes and exercisers consume some protein, as a meal or supplement, in the immediate period following resistance exercise.