Whole milk serves a few different functions. It is a complete meal and is an excellent post-workout drink for recovery and muscle building. It contains protein, fat, vitamins D and K, all necessary for performance and strength gains. It is an inexpensive form of supplementation; it is full muscle building properties and is ideal for trying to build mass. On top of all the good properties, milk is cheap, easy to find, and requires no preparation, so that it can be consumed immediately.
If you are lactose intolerant (actually a quite rare condition) whey protein is an ideal choice. Many forms of whey protein are lactose-free and therefore will not cause problems for those that cannot drink whole milk.
Whey Protein is a by-product of cheese manufactured from cow’s milk. It has the highest biological value of any protein, meaning that it passes through the stomach quickly and is rapidly absorbed by the intestines. For years it has been the staple of many athletes/bodybuilders’ supplement program.