What is whey protein?!
Question:
What is whey protein?
Answers:
Whey is a VERY fast-absorbing protein it is best to have it after your workout. The reason for this is because after a hard workout your muscles need to recover ASAP. Whey protein is quickly digested, this is what you want.
Casein (another form of protein from milk) is at the other end of the spectrum and is broken down slowly. This form of protein is best taken at night, for example so that protein is slowly absorbed overnight.
It is recommended you drink whey protein within the post "hour window" after workout to suppress cortisol (muscle eating stress hormone) levels. Eating within this window is important for maximal muscle growth and protein synthesis.