alpha-Lactalbumin Improves Sleep and Recovery after Simulated Evening Competition in Female Athletes

Purpose: This study aimed to determine the efficacy of alpha-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 +/- 43min; 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.