The effect of sleep deprivation and exercise load on isokinetic leg strength and endurance
- Cite this article as:
- Bulbulian, R., Heaney, J.H., Leake, C.N. et al. Europ. J. Appl. Physiol. (1996) 73: 273. doi:10.1007/BF02425487
Isokinetic leg strength and fatigue were measured in 24 male U.S. Marine Corps volunteers in a simulated sleep loss and unusually heavy work scenario. Knee extension and flexion peak torque (PT) were measured at three isokinetic speeds (1.57, 2.62 and 3.66 rad·s−1) followed by 45 consecutive maximal reciprocal contractions at 3.14 rad·s−1 to measure fatigue index (FI). All subjects were retested 2 days later following 30-h sleep deprivation (SD). The exercise group (n = 12) spent 25 1-h sessions performing computer tasks, filling out questionnaires and walked 1.61 km with a 50% gross body mass pack load, during each of the 25 sessions. The control group (n = 12) did likewise but did not exercise. Repeated measures ANOVA indicated that flexion PT at 1.57 rad·s−1 decreases (P < 0.013) after SD. Exercise did not affect Fl but did decrease PT. It was concluded that carrying a 50% load produces decrements in PT for both extension and flexion but more so for flexion. SD affected PT but had no effect on FI.