With post-workout nutrition, timing is everything. If you want major mass gains, you need to take advantage of the slim-but valuable-window of opportunity immediately after workouts. Because your muscles grow while they are recovering from the workout, and not during the workout, you need to feed them with a recovery supplement specifically designed to support muscular mass production. With Mass Factor that is exactly what you get! Here is why... Mass Factor has been designed to inject a burst of growth-stimulating protein and carbs into your muscles after consumption to feed the growth frenzy of the first stage. Then, the next wave of slower-absorbing protein gets pumped into your muscles to support the second-stage growth spurt. This "two-stage slower-absorbing activating system" is made possible through the use of "fast" and "slow" acting proteins and carbs. A blend of whey and casein provides the perfect protein combination, because research shows that whey protein is absorbed very rapidly into the body, while casein has a delayed absorption profile. Next, a specialized carbohydrate blend is used as the exclusive carb source. Why? Because it provides both a short and longer chain carbohydrate molecules. Short chains are absorbed rapidly and longer chains more slowly, feeding your muscles a continuous stream of clean carbs throughout both stages of the anabolic recovery phase. A combination of whey and casein-post-exercise-has been shown to increase the level of muscle protein synthesis during recovery over and above a standard carbohydrate supplement.