Abstract:
In this study we aimed to establish the usefulness
of the time constant of heart rate recovery (Tr) in the evaluation
of cardiovascular fitness. 15 male subjects exercised on
recumbent bicycle at three different workloads (75W, 100W
125W) where R-R intervals were monitored to determine Tr. In
order to find the maximal oxygen uptake (VO2max) of each
subject, oxygen consumption rate (VO2max) was recorded
throughout the treadmill exercise (10km/h). Based on VO2max ,
we classified the subjects into two groups: the “fit” group and
the “unfit” group. We found a significant difference in Tr
between these two groups only existed when the workload was
75W (p ≤ 0.01) and only at this workload did the R-R intervals
achieve stability during the 5 minutes of exercise. Furthermore,
we found the cut-off value for predicting cardiovascular fitness
at this workload was 55 seconds, with an associated sensitivity
of 85.7% and specificity of 87.5%.
