New research shows that in contrast to people who do not have the disorder, people who suffer from sleep apnea may not be capable of burning adequately high levels of oxygen during laborious aerobic exercise. Individuals who suffer from sleep apnea may also feel sleepy during the day because due to frequent disruption, night-time sleep is not adequately restorative.
The study, reported in the current issue of Journal of Clinical Sleep Medicine, shows that people with sleep apnea, in which breathing repeatedly starts and stops during slumber, have a lower peak oxygen uptake during aerobic activity than those who do not suffer from the sleep disorder.
People who suffer from apnea are more likely to be obese and thus would be expected to be less fit as well. The researchers, however, found that apnea patients had a reduced aerobic fitness, even compared with those of similar body mass indices.