Does physical activity influence heart rate variability and very-low-frequency components in Holter electrocardiograms?
When predicting cardiovascular prognosis using RR fluctuations, the confounding effect of physical activity must be accounted for.
The amount of RR variability and its slower fluctuations largely depend on physical activity, regardless of its regular or irregular occurrence. Attempts to predict cardiovascular prognosis on the basis of RR fluctuations should therefore take account of the confounding effect of physical activity since healthier subjects would probably be more active.
Luciano Bernardi (1996) studied this question.