The effect of intensity and duration of exercise bouts upon the electrophysical components of the cardiac cycle

Abstract

Purpose [line break] The purpose of this study was to investigate the effects of intensity and duration of physical training programs on the time intervals of the electrophysical components of the cardiac cycle. [line break] Procedure [line break] Fifty volunteer male college students between the ages of eighteen and twenty-four were randomly assigned to five experimental groups- four exercise groups and a control group. The exercise groups performed endurance training exercises three days per week for a six week period. All exercise training was done on a bicycle ergometer where the heart rate and workload was continuously monitored. Each group was assigned to one of four exercise programs identified as: twenty-five per cent intensity for ten minutes duration, seventy-five per cent intensity for ten minutes, twenty-five per cent for thirty minutes, and seventy-five per cent intensity for thirty minutes. In each case intensity was determined using the per cent differences between the resting and maximum heart rate. The cardiac interval components were evaluated prior to the conditioning program, and again at the completion of the program. The test consisted of simultaneous recording of the arterial pulse, phonocardiogram, and blood pressure during the condition of rest, while working and at one and one half minutes after exercise. ...