Effects of All Out-Cycling Bouts on Left Ventricular Function in Master Cyclists
Published on: 2018-11-03
The effects of different strenuous cycling bout’s time of training regimes on left ventricular function were examined in male healthy cyclists at the national level (57.3±5.2 yrs.). Methods: 43 Subjects were randomly assigned to perform four different strenuous cycling bouts in an increasing or decreasing order: 30, 60, 90, 120 sec or 120, 90, 60, and 30 sec on an electrical bicycle at a resistance corresponding to 80% of subjects’ maximal VO2 test. All subjects performed both the increasing and decreasing orders in two separate visits. Recovery times between exercises bouts in the increasing schedule were 3, 4 and 5 minutes compared to 5, 4 and 3 minutes for the decreasing schedule respectively. Results: There were significant interactions between bouts and schedule in heart rate, lactic acid accumulation, systolic and diastolic volumes. Cardiac responses indicate different response mechanisms of cardiac function during the two schedules. The decreasing schedule was characterized by higher mean heart rates (p<0.05), lower mean stroke volume (p<0.05) and lower mean end diastolic volumes (p<0.05). In both schedules mean end systolic volume and mean end diastolic volume decrease significantly (p<0.05) with increased time of performance. Conclusions: These data suggest that master cyclists, had a higher lactic acid, during the decreasing schedule with venous return is impeded. The lower venous return might have been caused by inadequate vasodilatation during early phase of decreasing order. Thus, in master cyclists, the decreasing schedule triggers better cardiac training responses than the increasing schedule.
Training intensity; cardiac output; left ventricular contractility; left ventricular volumes