Before I state my comment I just want you to realize that Diet and exercise is always changing.  So what the Pros said ten years ago has big chances that it is false today.  So this being said,  Protein shakes aren't what you really think they are.  If your buy a big jug of protein for around 50 or 60$ you are getting a big rip off!  It cost around 50$ just to make a 20g of real protein.  So the stuff they are selling you is not what you think.  My advice to you is eat naturel protein item like Eggs.  Eggs had have a bad reputation the last few years.  One boiled egg contains 6g of protein and the yoke is good for you as oppose alot of people thinking. (stay away from cartons of white eggs hey contains absolutly nothing, its as if your eating carboard)  Proteins is good for the muscle repair right after a work out.  After any training it is important to take in those protein regardless what your activity is.  I compete in Triathlon and after any of my workouts I just eat.  Hope this help you.

Cheers