Huang RJ, et al. - Authors studied 521 men by using structural equation modeling (SEM) and processed the measures of anthropometry, pulmonary function, overnight sleep polysomnography, and cardiopulmonary exercise testing to investigate the interaction between objective sleep disturbance and obesity, sedentary lifestyle, and lung dysfunction and if it was negatively correlated with cardiorespiratory fitness. They observed that disrupted sleep was directly and independently linked with low exercise capacity. Despite, sleep-disordered breathing was observed mediated indirectly by obesity and mutual interactions among obesity, lung dysfunction, and sedentary lifestyle and was linked to low exercise capacity. Hence, they recommended people with limited exercise capacity should undertake a sleep study, especially subjects with sleep-disordered breathing or insomnia.