Circulo-respiratory responses to different muscular exercises

Abstract

Six muscular exercises, i.e., pedalling sitting (PS), cranking sitting (CS), pedalling and cranking (PCC), cranking standing (CST), pedalling reclining (PR), and pedalling with back support (PBS) were compared to see the relationship between work patterns and bodily reactions. Five young males volunteered in the study. CST, CS, PR, PS, and PBS yielded 76, 72, 72, 87, and 97% of Vo2 max (PCC) respectively. Power output in arm work was about 70% of leg work. The ratio of VE/Vo2 in PS and PCC varied only between 22-24, while in CST, CS, PR, and PBS the ventilation equivalent decreased with the severity of exercise. At 40% Vo2 max (CST, CS, PR, and PBS) and 70% Vo2 max (CST, PR, and PS) the heart rates were about 145 beats X min-1 and 155 beats X min-1 respectively. Blood pressure was less in arm work than in leg work. PCC had a compensatory mechanism in lowering systolic blood pressure. At Vo2 max (PBS), the O2 debt was 8.911, and 3.96 and 6.48 l respectively at 40 and 70% Vo2 max (PBS); next highest values were observed in PR and CS, indicating inclusion of more isometric work component in CS, PR, and PBS. Slow component of the recovery Vo2 contributed largely to the total O2 debt. The net mechanical efficiency in most exercises ranged within 14-21%. At 40% Vo2 max the efficiency was high followed by a fall at 70% Vo2 max and again at Vo2 max a marginal improvement in efficiency was noted. Arm and leg work were better performed in upright sitting posture. PCC was beneficial to improve Vo2 max and to balance the physiological reactions.