In conclusion, exertional dyspnea is widely prevalent in otherwise healthy younger obese women. Dyspnea during exercise in obese women is strongly associated with an increased oxygen cost of breathing, which does not seem to be specifically or consistently correlated to obesity-related changes in pulmonary function, body composition, fat distribution, or pulmonary mechanics. In contrast to conventional thinking, exertional dyspnea in otherwise healthy younger obese women is not due to cardiovascular deconditioning. These findings could have an important influence on societal misconceptions of obese patients and on treatment strategies for overweight and obese patients who make up roughly 50% of the U.S. population.