Sure, you probably kill it while you’re at the gym, but are you repairing your body afterward? After a rigorous workout, especially one involving strength training, your body is in serious need of some nutrients to help it recover and grow. That’s where whey protein plays an essential role.

There are two proteins derived from milk: whey and casein. Whereas casein is a slow-dissolving protein, whey protein isolate is quickly absorbed into the body. Whey is also low in carbs and fat but high in protein, making it the ideal after-workout supplement.

Whey is great for recovery because it helps repair torn muscle tissue and build lean muscle. It also contains essential amino acids such as leucine, isoleucine, and valine. Studies have shown that whey also helps athletes lose fat in part because it better preserves their muscles. Whey is also very satiating, so it can help curb your appetite for hours after you exercise.

Why not just eat food after a workout? Solids take too long to digest when you’re looking to quickly feed your body within that crucial 30-minute window after a workout (basically, before your sweat dries). That’s why whey continues to be the king of proteins. If you’re lifting especially heavy or looking to gain mass, you might supplement your diet with slower-dissolving proteins as well, or consider a multi-phase protein blend that will continually feed your body protein over a number of hours.

Through Dec. 24, 2014, CFCOA is offering 20% off StrongerFasterHealthier whey protein in the store, as well as 20% off fish oil. Get them while you can!