If young, healthy guys eat 30 grams of casein protein — with or without an extra 2 grams of leucine — before bed after working out, it doesn’t actually help their muscles grow more overnight.

Pro

Against

Evidence from Studies

Supporting (1)

Community contributions welcome

Presleep dietary protein-derived amino acids are incorporated in myofibrillar protein during postexercise overnight recovery.

Randomized Controlled Trial

Human

2018 May 1

Contradicting (0)

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No contradicting evidence found

Gold Standard Evidence Needed

According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.

Source Study

Presleep dietary protein-derived amino acids are incorporated in myofibrillar protein during postexercise overnight recovery.

Score: 40

DOI: 10.1152/ajpendo.00273.2016

Similar Assertions

If young, healthy guys drink a protein shake with or without extra leucine before bed after working out, it doesn’t seem to boost muscle repair overnight any more than the protein alone.

95%

If young guys lift weights and then drink a protein shake with 30 grams of casein before bed, that protein actually gets used to repair and build their muscles while they sleep.

91%

If older guys around 72 drink a protein shake with 40 grams of casein before bed, it helps their muscles repair and grow overnight better than not having it.

91%

If young guys lift weights and then drink a protein shake with 30 grams of casein before bed, that protein helps fix their muscles while they sleep.

89%

If young, healthy guys drink a casein protein shake before bed after a long workout, their muscles build more overnight — both in the energy parts of cells and the actual muscle fibers.

85%