If young, healthy guys work out and then drink a whey protein shake based on their lean body weight, their bodies will absorb more amino acids than if they drank the same amount of cricket or pea protein.

If a young guy drinks a shake with 25 grams of whey protein, his body absorbs more essential amino acids over 6 hours compared to drinking the same amount of casein protein.

When healthy guys drink more whey protein, their bodies absorb more of an important amino acid called phenylalanine—about 10% more when they take a higher dose.

If you lift weights and drink a protein shake after your workout, one made only with fast-digesting whey might give your body a quicker boost of key muscle-building amino acids than a mix with mostly slow-digesting casein.

When rats exercised and then ate a small amount of whey protein hydrolysate, their muscles built protein faster than when they ate regular whey protein at the same dose.

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.