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...

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.

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.

Older women around 69 years old who drink a whey protein shake every day and lift weights three times a week for three months may gain more muscle, lose belly fat, and improve their overall metabolic health more than those who just do the workouts without the protein.

If young, active guys lift weights 4 days a week and eat the same total amount of protein, it doesn’t matter whether they have their casein protein late at night or earlier in the day — they’ll gain similar muscle and strength over 10 weeks.

After drinking whey protein shakes every day for a week, older women’s muscles kept building up new protein even on days they didn’t exercise—collagen protein didn’t do this at all.