The protein signal that tells your muscles to grow (mTOR) turns on just as well with plain protein as it does with protein plus sugar or alanine.

In healthy young adults, insulin alone cannot trigger key cellular processes for building proteins in muscle unless amino acids are also present, even though insulin still activates its initial signaling step.

When trained guys drink a special ketone drink after a tough leg workout (and also eat protein and carbs), their muscles send stronger 'grow' signals than when they drink a fake version — even though their insulin levels are the same.

Taking leucine — a protein building block — might turn on muscle-building signals in your muscles, but if you're already training and eating enough protein, it won't actually make you stronger, bigger, or recover faster.

When you lift weights, your muscles turn on a specific molecular switch called mTORC1, which helps build more muscle protein. But just because this switch flips on right after a workout doesn’t mean you’ll definitely get bigger muscles over time—it doesn’t always line up.

In young, healthy men who exercise recreationally, consuming leucine is linked to specific molecular changes in muscle cells that are thought to support increased muscle protein synthesis.