Purpose

This study aimed to determine the efficacy of α-lactalbumin (A-LAC) supplementation for improving sleep and performance recovery after simulated evening competition in female athletes.

Methods

Sixteen trained women (mean±SD: age, 27±7 yr; mass, 62±10 kg; stature, 167±8 cm) participated in this randomized double-blind three-arm crossover study. Participants completed a simulated evening competition before consuming either an A-LAC whey protein, whey protein placebo (PLA), or water control (CON) beverage. Sleep was monitored via polysomnography, and participants completed a series of physical, cognitive, and perceptual assessments before, and 14 and 24 h after simulated competition.

Results

Non-rapid eye movement stage 2 sleep increased after competition in A-LAC (pre, 199±44 min; post, 212±37 min) but decreased in CON (pre, 228±43 min; post, 195±40 min) and PLA (pre, 224±25 min; post, 211±35 min; P= 0.012). In addition, Yo-Yo Intermittent Recovery Test Level 1 distance improved over time in A-LAC (baseline, 664±332 m; 14 h post, 667±326 m; 24 h post, 781±427 m) compared with CON (baseline, 741±366 m; 14 h post, 648±351 m; 24 h post, 720±407 m) and PLA (baseline, 763±394 m; 14 h post, 636±366 m; 24 h post, 720±396 m; P< 0.001).

Conclusions

The findings indicate that A-LAC supplementation may be useful for retaining some sleep characteristics after evening competition, leading to improved physical performance in female athletes.