Many dietitians, bodybuilders and trainers agree that when you wake up in the morning your muscles need a fast source of amino acids to stop muscle loss after 7-8 hours on fasting and it’s a good time to take a water based protein shake.
This is because a insulated whey shake with water, can be digest in less than 1 hour without problems while a blend shake can take 1.5 or 2 hours and a casein one 3 hours or more. Some nutritionists also point out that the difference is that proteins are supergroups of amino acids, so putting regular protein (which is how it appears in any food) in your body takes longer to absorb because it has to “release” amino acids, instead most protein shakes directly containing amino acids their absorption is very fast so that in 20-45 minutes the shake may have been absorbed (which is not the same as digested).
Based on this an excellent breakfast for your muscles is a source of good carbohydrates such as a bowl of cooked oats and a water based whey protein shake. In total, about 260 calories with 30 grams of protein for the growth of your muscles.