Abstract des Autors

This study examined the relation between pedal frequency and cardiovascular responses during arm (AE) and leg (LE) ergometry. Twenty-six subjects completed three experimental sessions. Each session consisted of 10 min of steady-state exercise on AE or LE at 40, 60, or 80 rev·min-1. Oxygen uptake (VO2) and cardiac output (Q) were measured during each exercise. Arteriovenous oxygen difference (a-vO2diff) was calculated by dividing VO2 by Q. VO2 was greater at 80 than at either 40 or 60 rev·min-1 during both AE and LE. Q was greater at 60 than 40 rev·min-1 during AE and at 80 than 40 rev·min-1 during LE. a-vO2diff was greater at 80 than 40 or 60 rev·min-1 during AE, but remained unchanged during LE. It appears that the greater VO2 at 80 rev·min-1 during AE is due to an increase in peripheral O2 extraction. However, an enhanced systemic circulation may be the principal cause for the greater VO2 seen at 80 rev·min-1 during LE. Verf.-Referat