We would like to thank Krachler et al for their letter regarding our study “The Impact of Cardiorespiratory Fitness on the Obesity Paradox in Heart Failure.” Our original study demonstrated that the “obesity paradox” in heart failure was significant only in patients with poor cardiorespiratory fitness, as defined by peak oxygen consumption on cardiopulmonary exercise testing of ≤14.0 mg/kg/m ² . Krachler et al astutely point out that our measure of fitness relies on adjustment by total body weight, which may underestimate fitness levels; adjustment for lean body mass rather than total body weight has been shown to be a better predictor of outcomes in heart failure. We do not have measurements of body composition such as skin fold thickness or dual x-ray absorptiometry recorded in our heart failure cohort and, thus, are happy to learn of the article by Krachler et al, which outlines a method for estimating lean mass based on weight, height, and gender. We hope to use this method in future studies of obesity, cardiorespiratory fitness, and outcomes in patients with heart failure.