Could Sleep Apnea Impair Physical Fitness?
Patients with moderate to severe obstructive sleep apnea (OSA), regardless of body size, have lower aerobic fitness and exercise capacity than individuals without the disorder, according to a new study.
Although OSA has been associated with increased cardiovascular risk, its relationship to physical fitness is less well defined. While OSA’s link to obesity would seem to explain why individuals with the disorder are less fit, researchers hypothesized that it is OSA itself that inhibits exercise capacity, not the patient’s body mass index.
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“We believe the sleep apnea itself causes structural changes in [the] muscle that contributes to their difficulty exercising,” researchers wrote.1
For the study, 15 men and women with moderate to severe apnea and 19 participants with mild or no apnea were instructed to pedal a stationary bike at several difficulty increments and resistance levels to simulate biking up progressively steep hill.2
According to researchers, all participants were instructed to pedal to the point of exhaustion.
Then they measured the maximum amount of oxygen that each participant could absorb during strenuous exercise (VO2 max) and compared it to a person of the same gender, body mass index, and age without OSA.1,2
The study showed a 14% lower VO2 max among people with OSA compared to control participants.
The investigators noted that the measurements of VO2 max could help predict patients who are at a greater risk of heart attack and stroke; they said that VO2 max results could encourage early apnea interventions.1
The complete study is published in the November issue of Journal of Clinical Sleep Medicine.
-Michelle Canales
References:
1. UC San Diego News Center. Sleep apnea linked to poor aerobic fitness. November 24, 2014. http://ucsdnews.ucsd.edu/pressrelease/sleep_apnea_linked_to_poor_aerobic_fitness. Accessed November 26, 2014.
2. Beitler JR, Awad KM, Bakker JP, et al. Obstructive sleep apnea is associated with impaired exercise capacity: a cross-sectional study. J Clin Sleep Med. 2014 November [epub ahead of print] doi: http://dx.doi.org/10.5664/jcsm.4200.