Litsov A N, Saraev I F
Kosm Biol Aviakosm Med. 1980 Jan-Feb;14(1):17-23.
Physiological functions, work capacity and sleep characteristics of six healthy test subjects were studied for 30 days. The test subjects adhered to one of the three different regimens (1--sleep from 2.00 a.m. to 10.00 a.m., 2--sleep from 6.00 p.m. to 2.00 a.m., and 3--sleep from 10.00 a.m. to 6.00 p.m.) which were aggravated by 64 hr or 72 hr vigilance during the experiment. The studies demonstrated general and specific changes in physiological functions, work capacity and sleep closely associated with the fact how far work-rest cycles were shifted and how long they were applied. Prolonged vigilance caused similar changes in physiological functions, work capacity and sleep. The test subjects showed very poor tolerance to an alteration in the work-rest cycle combined with sleep deprivation.