Excess weight causes sleep apnea. Exercising (usually) helps you lose weight. Given this knowledge, it would be safe to say that exercising reduces weight, which then improves sleep apnea. Although this is likely true for many people, there are case studies that suggest exercising alone, without any weight loss, improves sleep apnea. Could we test whether this is true? Using previously published studies on exercise and sleep apnea, a team of researchers from South Carolina and Pittsburgh did just that.
The data from five independently-conducted studies were combined to create one large dataset of 129 participants. Each study examined the effects of supervised exercise regimens on sleep apnea severity. Each participant’s body mass index (BMI), sleepiness, sleep quality (a percentage of time spent asleep over time in bed), and V02 max (a measure of how much oxygen the body can take in and higher = better) were also assessed. These measures were taken before and after the supervised exercise and compared.
An overall analysis of the large dataset showed that exercise greatly reduced apneas, improved sleep quality, improved V02 max, and reduced sleepiness. Interestingly, BMI was only slightly reduced.
This study brings up a few interesting points of discussion. First, exercise is good for your sleep on basically all levels. Additionally, exercise improves sleep apnea without necessarily reducing BMI. However, it is necessary to point out that although the weight of the subjects was not greatly reduced, they may have simply lost fat and gained muscle in its place. If that were the case, weight (and thus BMI) would not be reduced, but there would be less fatty tissue to block the airway and cause apneas. Perhaps future studies would benefit from separating fat weight from muscle weight in the final calculations. Despite the previous caveat, it is still crucial to repeat that exercise absolutely improves sleep apnea – so get out there and start moving!
Iftikhar, I. H., Kline, C. E., & Youngstedt, S. D. (2014). Effects of Exercise Training on Sleep Apnea: A Meta-analysis. Lung, 192(1), 175-184.