Dietary proteins with high leucine content, like whey protein, can induce muscle protein synthesis even without intense exercise.

“Remember, even if you haven't been exercising intensely or doing any resistance training, and by the way, you should be doing resistance training and cardiovascular training, but independent of exercise, dietary protein, in particular, dietary proteins that contain high amounts of leucine, or I should say, relatively high amounts of leucine, like whey protein, will help induce so-called muscle protein synthesis, which is generally good for us, again, and it's occurring even if we're not”