Author(s): KOMAREK, Z., WIECEK, M., SOKULSKA, N., LIPOWSKA, M., SPIESZNY, M., HOLDA, M., FILIP-STACHNIK, A., Institution: AKADEMIA WYCHOWANIA FIZYCZNEGO IM. BRONISLAWA CZECHA W KRAKOWIE, Country: POLAND, Abstract-ID: 1952

INTRODUCTION:
Strong evidence indicates that sleep deprivation and chronic sleep restriction has a negative impact on athletes performance. However, little is known about the effect of sleep restriction on female athletes. The aim of this study was to analyze the effects of 3-hour early sleep restriction on physical performance, motivation, testosterone/cortisol ratio, inflammation, and muscle damage markers in highly-trained female soccer players.
METHODS:
Eight female soccer players participated in a randomized, counterbalanced, and crossover experiment. Each athlete performed two identical experimental sessions in two conditions: a) after habitual sleep (HS) and b) after 3-hour sleep restriction (SR) and performed the following tests: a) countermovement jump; b) sprint test (0-30 m); c) Zig Zag Test without ball; d) Zig Zag Test with ball and d) Yo-Yo intermittent recovery test level 1. Each experimental session was preceded by an evening standardized soccer training (ST). Blood was collected: a) before ST (T0); b) after ST (T1) and c) before physical tests (T2) to evaluate the activity of creatine kinase and lactate dehydrogenase, concentration of myoglobin, C-reactive protein, cortisol, and testosterone.
RESULTS:
T-test showed a significant increase in the 10-m sprint time in SR condition in comparison to HS condition (1.905 ± 0.080 vs 1.890 ± 0.089 s, respectively; p=0.036), without significant changes in other physical tests (p>0.05). In addition, a significant decrease in subjective reports on “physical strength” (2.8 ± 0.7 vs 3.8 ± 0.7 a.u., respectively; p= 0.017) and “muscle soreness” (6.1 ± 0.9 vs 5.0 ± 1.6 a.u, respectively; p=0.044) was observed in SR condition in comparison to HS condition. There were no statistically significant differences between HS and SR conditions in level of any biochemical markers (p>0.05).
CONCLUSION:
The present study indicates that a 3-hour restriction on early sleep can negatively affect some aspects of physical performance and motivation in highly trained female soccer players, but has no effect on testosterone/cortisol ratio, inflammation, and muscle damage markers. Nevertheless, athletes and coaches should take into consideration the potential effects of one night with sleep restriction.