Effects of Exercise, Bedrest and Napping on Performance Decrement During 40 Hours


  • This search was supported by [he Advanced Research Projects Agency of the Department of Defense under Order no. 1596, and by the Department of [he Navy. Bureau of Medicine and Surgery, under Work Unit M43US.07-3008DACS. The views and conclusions contained herein are those of authors and should not be interpreted as necessarily reflecting (he official policies, either expressed or implied, of the Defense Advanced Research Projects Agency, the Department of the Navy, or the U. S, Government.

  • The authors thank Julio Moses, Bill Jensma. Ray Hilbert. Don Irwin, Marion Austin, Korey Greene, Gary Howell, and Mall Sinclair for assistance in the planning and execution of this study.

Address requests for reprints to: Ardie Lubin, Ph.D., Naval Health Research Center, San Diego, California 42152.


Young male Naval volunteers were denied normal noclurnal sleep and maintained on a 60-min lreatment-160-min testing schedule during 40 consecutive hrs. Ten subjects bicycled, 20 subjects controlled EEG activity during bedrest, and 10 subjects napped. Eight measures of addition, auditory vigilance, mood, and oral temperature were obtained. The Bedrest group showed significant impairment on all eight measures, and thus, gave no support to lite forced-rest theory of sleep function. The Exercise group was worse than the Nap and Bedrest groups for all measures. In spite of fragmented, reduced sleep (about 3.7 hrs per 24 hrs), the Nap group had no impairment on six of the measures. The results suggest that exercise increases the impairment due to sleep loss, and naps reduce or remove this impairment. Bedrest is not a substitute for sleep.