Figure 4.

Stroke volume (a), left ventricular (LV) volumes (b), intraventricular pressure gradients (c), heart rate (d), peripheral beat volume (e), and blood volume (f) at rest and during prolonged exercise in the progressive dehydration and euhydration control trials. Cardiac images for intraventricular pressure gradients were successfully analyzed in six of the eight subjects, and blood samples were successfully obtained in seven of the eight subjects. Therefore the intraventricular pressure gradients data and blood volume data are from those six and seven subjects, respectively. The other parameters are from eight subjects. Data are means ± SEM. *p < .05 versus 30 min; ^† p < .05 versus euhydration control