Figure 3.

Sample flow volume loops from individuals at peak exercise. A, Control obese (CO) subjects with EFL. B, CO subjects without EFL. C, Fit obese (FO) subjects with EFL. D, FO subjects without EFL. EFL was observed in four (three women and one man) FO and five (three women and two men) CO subjects; however, the degree of flow limitation was mild (EFL < 25% V_t) and was not different between the FO and CO groups (13% ± 6% V_t vs 16% ± 7% V_t, respectively). E, Dynamic lung volumes (end-inspiratory lung volume and end-expiratory lung volume) during the peak exercise test (rest, submaximal exercise, and peak exercise). EELV = end-expiratory lung volume; EFL = expiratory flow limitation; EILV = end-inspiratory lung volume; F_B = breathing frequency; F/V = flow volume; O₂sat = oxygen saturation; P_etCO₂ = end tidal CO; VO₂ = oxygen uptake; V_t = tidal volume; WR = work rate. See Figure 1 and 2 legends for expansion of other abbreviations.