Received May 6, 2004
Revised June 23, 2004
Accepted after revision August 12, 2004

¹ university of cagliari
² university of torino

^* To whom correspondence should be addressed. E-mail: crisafulli{at}tiscali.it.

	Abstract

We aimed at investigating hemodynamics during active and passive recovery following repeated bouts of supramaximal exercise. Seven male athletes underwent two sessions of supramaximal exercise which consisted of a warm-up and of five bouts of cycling at the maximum speed possible for 30 seconds against a resistance equivalent to 150% of the maximum workload achieved in a previous incremental test. Bouts were separated each other by one minute of recovery and followed by ten minutes of recovery which were either active (pedalling at 40W) or passive (completely rest seated on the cycle). Hemodynamics were evaluated by means of impedance cardiography. Heart rate (HR), stroke volume (SV), cardiac output (CO), mean blood pressure (MBP), thoracic electrical impedance (Z0) as an inverse index of central blood volume, and systemic vascular resistance (SVR) were assessed. The main findings were that active recovery, with respect to passive one, induced higher changes from baseline in HR (+29.1 ± 4.5 vs. +15.6 ± 2.9 bpm at the 10th minute of recovery, p<0.05), SV (+19.9 ± 5.6 vs. -6.4 ± 3.3 ml, p<0.01), and CO (+3.8 ± 1.2 vs. +0.4 ± 0.2 lmin-1, p<0.01). Furthermore, MBP was similar between the two kinds of recovery despite Z0 increased during passive recovery compared to the active one. These results suggest that the faster hemodynamic recovery towards baseline and the decrease in cardiac pre-load during passive recovery may be successfully prevented by cardiovascular regulatory mechanisms which include an increase in SVR thus avoiding a drop in blood pressure.

Key Words: Blood pressure, Circulation, Exercise