SLEEP-DEPRIVATION - EFFECTS ON WORK CAPACITY, SELF-PACED WALKING, CONTRACTILE PROPERTIES AND PERCEIVED EXERTION

The primary purpose of this study was to examine the effect of a 48-ho ur period of sleep deprivation on the performance of selected physical work tasks [30-45% of maximum oxygen consumption (VO(2)max)]. In addi tion, this study assessed the effect of continual performance of physi cal work during sleep deprivation on standardized physiological and ps ychological test scores. Nineteen male subjects performed six differen t physical tasks, designed to involve all major muscle groups, during a 48-hour period of sleep deprivation. Fourteen subjects served as sle ep-deprivation controls. Performance on all physical work tasks decrea sed significantly. Neither sleep deprivation (SD) or sleep deprivation in conjunction with continuous physical work (SDW) had any effect on muscle contractile properties, anaerobic power measures or resting blo od glucose and lactate concentrations. Only SD subjects demonstrated a decline in cardiorespiratory function. Self-selected walking pace dec reased and perceived exertion increased significantly in the SDW group . Positive and negative mood scores were adversely affected in both gr oups, the total change being greatest in SD subjects. The results indi cate that performance of physical work tasks requiring 30-45% VO(2)max declines significantly over a 48-hour period of sleep deprivation. Ho wever, maximal physiological function is not unduly compromised by eit her the work tasks in conjunction with sleep deprivation or by sleep d eprivation alone.