Horne J A, Porter J M
Electroencephalogr Clin Neurophysiol. 1976 Feb;40(2):178-84. doi: 10.1016/0013-4694(76)90162-0.
The effect standardized exercise had upon sleep was studied with eight subjects. A pilot study assessed individual work capacity by the sub-maximal estimation of VO2 max. In the main study each subject performed the exercise, once a.m. and once p. m., on different days. Sleep was scored into stages and an additional sub-division of stage 2 containing 10-20% by time of delta. Comparison with baseline showed no significant whole night changes with any criteria following either a.m. or p. m. exercise. After p.m. exercise there was a significant increase in stage 3 for the first half of the night. It was concluded that ensuing wakefulness following early daytime exercise is sufficient for recovery, but late daytime exercise may result in an intrusion of recovery into initial sleep. Sleep is not seen to be necessary for recovery from muscular fatigue.
