Example of rest and peak exercise flow-volume responses in a healthy, average fit adult plotted within the maximal flow-volume loop

Example of rest and peak exercise FV responses in a healthy, average fit adult plotted within the MFVL. Key features of the minute ventilation response in the healthy adult include the following: (1) a drop in the EELV due to the recruitment of expiratory muscles; (2) an increase in Vt through equal encroachment on inspiratory and expiratory reserve volumes (IRV and ERV, respectively); (3) expiratory flow rates generally well within the maximum available flow rates (especially at the higher lung volumes); (4) avoidance of high EILVs (a high elastic load) or extremely low EELVs (reduced compliance and airway closure); and (5) inspiratory flow rates that are well within the maximal available flows.