Author(s): GURUHAN, S.1, ATALAY, N.A.1, HIRATA, R.2, ANDREUCCI, A.2, TOR, O.B.1, RATHLEFF, M.S.2, Institution: GAZI UNIVERSITY, Country: TURKEY, Abstract-ID: 2320

INTRODUCTION:
Sleep is an essential component for optimizing health and sports performance. It has been reported, however, that athletes experience more sleep disturbances than non-athletes [1,2] For athletic performance, it is important to study how total sleep deprivation (TSD) affects eccentric contraction, which plays a major role in increasing strength and hypertrophy and preventing injuries [3]. The aim of this study was to investigate the effects of TSD on eccentric muscle strength and activation in hamstring and quadriceps.
METHODS:
Twenty-one recreationally active individuals (10 males and 11 females, 21,05±1,46 year, 21,99±2,89 kg/m2) with good sleep quality (Pittsburgh sleep quality index and 5-point Likert scale) were enrolled in the crossover study. Each participant performed two test sessions with a 2-week washout period. The first test was performed in 2 hours after waking up. The second test was performed at the same time with the first one after 24 hours of sleep deprivation. The participants performed 5 repetitive eccentric contractions (900/s) using the isokinetic system for hamstring and quadriceps muscle groups in both prone and supine positions, respectively. Surface electromyography (Noraxon Inc., USA) was used to record the activation of the Biceps femoris (BF), Semitendinosus (ST), rectus femoris (RF), vastus lateralis (VL) and vastus medialis (VM) during eccentric contractions. The peak torque and muscle activity was calculated for statistical analysis using 2nd, 3rd and 4th repetitions of each test.
RESULTS:
There was no statistically significant difference between normal sleep and sleep deprivation states in terms of eccentric muscle strength of hamstring (p=0.088) and quadriceps (p=0.304) muscles, however, a decremental trend was observed. The muscular activation of the VL muscle during the isokinetic eccentric exercise test decreased significantly (p=0.045) in the sleep deprivation state compared to the normal sleep state, while there were no significant differences between normal sleep and sleep deprivation states in terms of muscular activation of the RF, VM, BF and ST muscles (p>0.05).
CONCLUSION:
Our study showed no differences in the eccentric strength of hamstrings and quadriceps muscle groups, however, a decrease in the activation of VL following a 24-hour-sleep deprivation. Therefore, eccentric exercise programs may be more tolerable in the morning hours and show muscle specificity in TSD.