Although sleep often is disturbed in persons with chronic fatigue syndrome (CFS), activity-related exacerbation of symptoms is not related to poor sleep. In fact, persons with CFS often sleep better after engaging in exercise.
Togo and associates studied a group of 17 women with CFS and 16 healthy controls. Participants underwent overnight polysomnography on a regular (baseline) night and a night after maximum exercise.
Baseline total sleep time was similar for everyone, but the women with CFS had less rapid eye movement, spent more time in stage 1 sleep, and had a longer awake stage, indicating poorer quality sleep. Sleep was better after exercise than at baseline in both groups. On the postexercise night, the patients with CFS woke up less often and spent less time in stage 1 sleep. However, they still spent more time in arousal and stage 1 sleep than controls, and sleep efficiency was low. They also reported more sleepiness, fatigue, and pain. The results were stratified on the basis of self-reported morning sleepiness; those who felt less sleepy had improved sleep structure.
The authors noted that awareness of exercise’s possible role in improving sleep should help patients increase their activity without worrying about negative health consequences.
