If you're a guy who lifts weights, drinking a protein shake after your workout with different mixes of fast- and slow-digesting milk proteins — like whey and casein — gives you about the same muscle and strength gains, even if your body processes the amino acids differently.

If you're a guy who lifts weights, drinking a protein shake after your workout with different mixes of fast- and slow-digesting milk proteins — like whey and casein — gives you about the same muscle and strength gains, even if your body absorbs the amino acids differently.

If guys who already lift weights drink a 20g protein shake after working out for 9 weeks, they’ll gain more muscle and get stronger—even if the protein is a mix of fast- and slow-digesting types.

If female college athletes who lift weights drink a protein shake with 24 grams of protein before and after workouts for eight weeks, they’ll get stronger in their upper body — especially if they use whey protein instead of casein.

For female college athletes who lift weights, taking 24 grams of whey or casein protein before and after workouts for eight weeks leads to the same results in muscle, strength, and performance — so both types work just as well.

If female college athletes who already lift weights drink a protein shake with 24 grams of protein right before and after their workouts for eight weeks — while following a specific 4-day workout plan — they’ll likely gain about 1.4 to 1.5 kg of muscle and lose 1 to 2% body fat.