Studies have shown that when people take whey protein before and after working out, they get significantly better results than if they did not take it. After a workout, the body is looking for branched chain amino acids, which are found in whey protein. When it does not find the BCAAs, a person feels fatigued.Â
A 2009 study at McMaster University in Canada found that participants who took whey protein after exercise saw 122 percent greater muscle protein synthesis than those who took other kinds of protein. In another study, the Minnesota Applied Research Center found that subjects who consumed whey protein 20 minutes before breakfast and 20 minutes before dinner lost more body fat than subjects who did not.
Not everyone agrees that pre- and post-workout consumption is best, however. At those times, the body needs carbohydrates more than it needs proteins, so it is better to take whey throughout the day, advises Barbara Lewin, a dietitian and sports nutritionist for professional sports leagues.