The body is a well-functioning machine. However, it is a very complicated machine. We like to picture things working in a linear fashion: when people exercise, they lose weight. Unfortunately, though, things can be more complicated. Certain factors within the body may interact, leading to inefficiencies in the way the body responds to physical exertion. Underlying factors, such as obesity, lead different bodies to react to exercise in different ways. People who suffer from sleep apnea need exercise in order to lose weight and lower sleep apnea severity. Ironically, the obesity that they are trying to fight may actually affect the way that their body responds to exercise. Because of this, a team of researchers set out to examine how obesity and sleep apnea may interact in this way.
In this study, children were used to assess the effects of both obesity and obstructive sleep apnea (OSA) on exercise capacity, meaning how long it takes for them to reach their physical peak. Each subject had previously undergone an overnight sleep study and about half had been diagnosed with OSA. Importantly, though, not all of the children with OSA were considered obese. Bodily measurements were taken of these 71 subjects and they were questioned on their regular physical exercise. Cycling against resistance was used to test exercise capacity. Heart and breathing measurements were taken during this test and were compared across groups.
Results showed a relationship between decreased exercise ability, sleep apnea severity, and weight. Obesity was a stronger determinant of exercise function, but sleep apnea contributed to subjects having lower heart rate functioning during exercise when compared to those without OSA, suggesting abnormal bodily response to exercise1.
As mentioned, exercise is more crucial to some people than others. Namely, those who are overweight and suffer from sleep apnea are in more dire need for exercise than those who are fit and healthy. Additionally, obese children, who are already at a high risk for developing many bodily deficiencies down the line, need to lose weight even more. What this study suggests is that, unfortunately, this population must work even harder to lose weight compared to an obese population without OSA. This makes it particularly important to intervene with obesity early and efficiently – and, of course, to keep up with PAP treatment in the meantime.
References:1. Pre-publication: Journal Sleep: Effects of obstructive sleep apnea and obesity on exercise function in children