This is a great article from the University of Massachusetts Strength & Conditioning Department and it is what I truly believe works.  No need for me to try and summarize this, it is well written and explains things very clear.  One thing I may say is that if you are overweight, this is not the right plan for you.  This is geared toward those who exercise at an intense level and want to add lean muscle to their body.  Women, don't be turned off by this " add bulk/lean muscle" term.  By adding lean muscle you are going to look and feel great.  For the guys, time to BULK! Remember, nutrition has general rules but every individual is different.  Speak to someone who can guide you based on your fitness levels and goals.... Read the article and enjoy your workouts.... Nutrients For Athletic Performance