Author(s): DEL VAL MANZANO, M., MONTALVO-ALONSO, J.J., GONZALO-ENCABO, P., VALADÉS, D., FERRAGUT, C., PÉREZ-LÓPEZ, A. , Institution: UNIVERSIDAD DE ALCALÁ, Country: SPAIN, Abstract-ID: 2535

INTRODUCTION:
Nightly rest is essential for preserving both physical and mental health. Despite its importance, nearly 45% of adults in Western countries do not achieve the recommended 7 to 9 hours of sleep per night. This is of special interest in athletes who have a higher predisposition to experiment with poor sleep or sleep deprivation, which cause a reduction in exercise performance. However, the effect of sleep deprivation on exercise performance is mainly obtained from evidence in men. Thus, this study aimed to examine sex differences in the impact of total and partial sleep deprivation on muscular strength, power, and endurance performance in resistance-trained participants.
METHODS:
Twenty-four resistance-trained participants (age: 22.1±3.3 years; sex (F/M): 12/12; training experience: 3.4±2.4 years) took part in a randomized, cross–over and counterbalanced trial with four sleep conditions: 8h normal sleep at home (SH) and the remaining three at the laboratory: normal sleep 8h (SL), early sleep deprivation 4h (pSD) and sleep deprivation 0h (SD). After each experimental condition, participants performed a muscular strength and power, and muscular endurance tests in the bench press and back squat exercises using a linear transductor. The muscular strength and power test was performed at 25%, 50%, 75%, 90% and 100% of 1RM loads, while the muscular endurance test was assessed for both exercises at 65% 1RM, performing one set until task failure. Velocity and power production were obtained in all tests. Dietary and physical activity habits were replicated 24 hours before the trials.
RESULTS:
In the muscular strength and power test at 50%1RM, a condition effect was found in both bench press and back squat exercises for Vmean, Vpeak and Time to Vpeak (P<0.048, ηp2>0.10). These effects were only found in male participants when comparing in both exercises SH and SL to pSD in Vmean (11-12%, P<0.048), Vpeak (7-10%, P<0.049) and time to reach Vpeak (-7–15%, P<0.049), and SL to SD in back squat exercise for Vmean (10%, P=0.048), Vpeak (7%, P=0.008) and time to reach Vpeak (-11%, P=0.050). In muscular endurance test, condition effect was found in the back squat exercise for Vmean, Vmax, Time to Vpeak, Wmean, Wpeak, and time to Wpeak (P<0.01, ηp2<1.61), differences that were only found in female participants when comparing SH and SL to PSD and SD in Vmean (10–12%, P<0.025), Vpeak (9–12%, P<0.02), Time to Vpeak (-13–15%, P<0.05), Wmean (10–11%, P<0.05), Wpeak (11–14%, P<0.04) and time to Wpeak (-14–16%, P<0.05).
CONCLUSION:
In conclusion, performance reduction in muscular strength, power and endurance performance caused by total and partial sleep deprivation occur differently according to sex. While male participants experienced a reduction in muscular strength and power performance, particularly at moderate loads (50%1RM), in females the reduction in performance occurred in muscular endurance test.