Cardiodynamic responses during seated and supine recovery from supramaximal exercise.

The cardiodynamic responses of 9 healthy men (mean age +/- SD, 22.3 +/- 2.0 yrs) were measured during seated and supine passive recovery following the Wingate Anaerobic Power Test (WAPT). Stroke index (SI) was determined noninvasively using impedance cardiographic techniques. During the initial stages of seated recovery, SI progressively increased (1 min, 60.4 +/- 6.6 ml/m2; 3 min, 64.6 +/- 5.9 ml/m2) and achieved peak levels by 5 min (70.5 +/- 6.2 ml/m2). Between Minutes 3 and 10 of seated recovery, SI was significantly (p < or = 0.05) higher than the preexercise value (46.0 +/- 4.0 ml/m2). A similar response pattern for SI was observed during supine recovery. The systemic vascular resistance index (SVRI) decreased by 101% and 114% from preexercise baseline values after 1 min of recovery in the supine and seated postures, respectively. The persistent rise in SI during the first 10 min of passive seated recovery may be explained by the sustained attenuation in SVRI coupled with the anticipated residual myocardial inotropic effects following the WAPT.