FIGURE 1.

Ventilatory, respiratory and perfusion responses during prolonged intense exercise with varied hydration status. Pulmonary ventilation, breathing frequency, tidal volume, alveolar ventilation (${\dot{V}}_{\mathrm{A}}$), cardiac output ($\dot{Q}$) and ${\dot{V}}_{\mathrm{A}}$/$\dot{Q}$ ratio during the progressive dehydration and euhydration control trials. Data are shown as the mean ± SD for seven subjects, except for ${\dot{V}}_{\mathrm{A}}$ and ${\dot{V}}_{\mathrm{A}}$/$\dot{Q}$, where data are from six subjects. ^*Significantly different from 20 min, P < 0.05. ^†Significantly different from euhydration control, P < 0.05