PULMONARY PHYSIOLOGY

In contrast to the widespread belief that all obese adults are inactive, there are many obese individuals who exercise rigorously, compete in endurance races, and potentially have high levels of cardiorespiratory fi tness (CRF). However, it is unclear whether this group of endurance-trained obese individuals encoun-ters obesity-related respiratory limitations. 1-4 End-expiratory lung volume (EELV) increases in obese adults at or near maximal exercise, 5-7 which may be in response to the presence of expiratory fl ow lim-itation (EFL). 8 The high ventilatory demand in trained athletes may exacerbate their work of breathing, as well as their risk of developing EFL. 9-11 However, little is known about CRF in “fi t and obese ” individuals; in addition, the mechanical mechanism by which they are able to generate the high ventilatory demand associate