Evaluation of cardiorespiratory fitness and respiratory muscle function in the obese population.

Cardiorespiratory fitness (CRF) is one of the most important health metrics in apparently healthy individuals, those at increased risk for cardiovascular (CV) disease and virtually all patient populations. In addition to CRF, a host of other variables obtained from aerobic exercise testing provides clinically valuable information. Individuals classified as obese (i.e. a body mass index ≥30 kg/m(2)) have varying degrees of CV, pulmonary and skeletal muscle dysfunction that impact CRF and other key aerobic exercise testing variables. Moreover, there is now evidence indicating inspiratory and expiratory respiratory muscle function, even in the absence of interstitial lung disease, is potentially compromised as a result of obesity. When obesity-induced respiratory muscle dysfunction is present, it has the potential to contribute to the limitations in CRF. The current review will discuss aerobic exercise testing and the assessment of respiratory muscle function in the obese population.