Exercise may improve obstructive sleep apnea (OSA) severity, even in the absence of weight loss. The less severe the OSA, the better patients may feel in the daytime. This article in the August edition of the Journal of Clinical Sleep Medicine is about a study done to see if exercise training can improve daytime functioning even without reducing OSA severity.
In the study, they had a group of people do supervised exercise for 12 weeks versus the control group that did only stretching for 12 weeks. The two groups of participants were similar with the exception of their baseline sleepiness scores, with the exercise group reporting a little more sleepiness than the stretching group.
The results of the study showed that at the end of the 12 weeks, the OSA severity was 25% lower in the exercise group. The exercise group also had less depressive symptoms, less fatigue, and more vigor than the stretching group. Exercise training caused a lowering if subjective sleepiness, but this was not statistically significant. Exercise training improved physical functioning, vitality, and mental health as measured by questionnaires. Interestingly, there was no difference in participants performance on tests of cognition with exercise versus stretching.
Now you may say that the improvements in exercise were due to OSA severity reduction, not because of the exercise itself as the authors proposed. But, only improvement in fatigue was linked to reduction in OSA severity in the exercise group. All of the other improvements occurred in the exercise group even when the OSA severity remained the same.
These findings are exciting, because not everyone feels better on CPAP. Perhaps exercise may improve their functioning, even though they still have OSA.