Research summary · Nutrition and hydration
Pre-sleep milk proteins did not measurably change sleep in female athletes
Twenty-one of 25 recruited female collegiate athletes completed four conditions: casein, alpha-lactalbumin, carbohydrate and a low-energy placebo before bed. Each condition lasted three nights. A wrist-worn device and morning questionnaires tracked sleep and recovery over the crossover trial.
- Publication year
- 2026
- First published online
- Publication type
- Randomized double-blind placebo-controlled crossover trial
- Journal
- Journal of the International Society of Sports Nutrition
- Population / context
- NCAA Division I women · Sleep and recovery
What the publication reports
The treatments produced no statistically significant differences in sleep duration, sleep efficiency, sleep-onset latency, resting heart rate, heart-rate variability or subjective recovery. The small glucose-monitoring subgroup likewise showed no clear treatment difference. The study found neither a detectable sleep benefit nor impairment from these short feeding periods.
Limits and interpretation
Three nights per condition and 21 completers cannot establish long-term effects or exact equivalence. Sleep was measured with a consumer wearable rather than polysomnography, and glucose data came from only six athletes. Findings should not be generalized to every bedtime meal or athlete population.
Read the source
Consult the original record for the full author list, methods, references, funding and competing-interest disclosures.
Pre-sleep milk-derived proteins do not impair sleep or recovery in elite female athletes
Original publication / indexed recordPMID: 42897977DOI: 10.1080/15502783.2026.2746899Full text at the sourceReader discussion
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