Sleep Apnea Linked to Poor Aerobic Fitness


Do you find yourself out of breath while you exercise, no matter how much you work out?  It may not be because you’re out of shape… Maybe sleep apnea is the culprit!

A study done at the University of California San Diego, and detailed in the Journal of Clinical Sleep Medicine, showed that people with sleep apnea have reduced aerobic fitness, or a lower peak oxygen uptake during aerobic activity, compared with those who do not.

Fifteen men and women with a range of sleep apnea symptoms participated in the study.  They were evaluated on the severity of their sleep apnea as well as checked for other sleep disorders, so as not to confuse the research results.  Interestingly, while those who have sleep apnea are more likely to be obese and, as such, less aerobically fit, the study showed that those with sleep apnea were still less aerobically fit than those with a similar body index. This is because, as Jeremy Beitler, who is the lead author of the study says, “We believe the sleep apnea itself causes structural changes in muscle that contributes to their difficulty exercising.”

The study’s participants pedaled on a stationary bike at increasingly higher levels of resistance until they reached the point of exhaustion, with researchers finding that those with sleep apnea had on average a 14% lower VO2 max than those without the sleep disorder. VO2 max is defined as the maximum rate of oxygen consumption as measured during incremental exercise.

Furthermore, this study showed that the number of times a person stopped breathing at night because of his or her sleep apnea for 10 seconds or more per hour of sleep could predict 16% of the variability observed in the group’s peak VO2.

VO2 max measurements may be an early sign for those at higher risk of stroke and heart attack. Therefore, hopefully these findings can motivate people to get tested for sleep apnea.  Doing so, and treating the sleep disorder, can not only lower the risk of stroke and heart attack, but also allows for an overall better quality of life.

So, if you’re finding yourself huffing and puffing no matter how long you’ve been trying to get in shape, perhaps it’s time to get tested to see if you have sleep apnea!


Source: Jeremy R. Beitler, Karim M. Awad, Jessie P. Bakker, Bradley A. Edwards, Pam DeYoung, Ina Djonlagic, Daniel E. Forman, Stuart F. Quan, Atul Malhotra.Obstructive Sleep Apnea Is Associated with Impaired Exercise Capacity: A Cross-Sectional Study. Journal of Clinical Sleep Medicine, 2014; DOI:10.5664/jcsm.4200