Research summary · Nutrition and recovery
Presleep whey and sleep after resistance exercise
Nine resistance-trained adults, including four women, completed three exercise sessions followed by 40 g of whey, casein or an energy-matched carbohydrate drink before bed. Sleep was assessed with actigraphy and questionnaires.
- Publication year
- 2026
- First published online
- Publication type
- Randomized double-blind crossover trial
- Journal
- International Journal of Sport Nutrition and Exercise Metabolism
- Population / context
- Resistance training; women and men
What the publication reports
Whey improved several sleep measures and reduced next-day soreness compared with carbohydrate, but did not significantly outperform casein. Exercise performance, heart-rate variability and gastrointestinal symptoms did not differ clearly between conditions.
Limits and interpretation
This very small, acute study cannot establish lasting sleep benefits or superiority of whey over casein. Actigraphy does not provide the sleep-stage information available from polysomnography. The tested amount is a research protocol, not an individual prescription.
Read the source
Consult the original record for the full author list, methods, references, funding and competing-interest disclosures.
Presleep Whey but Not Casein Protein Ingestion Improves Sleep Quality After Resistance Exercise When Compared With an Isocaloric Control in Resistance Trained Individuals
Original publication / indexed recordPMID: 42413910DOI: 10.1123/ijsnem.2025-0205Reader discussion
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