Subjects

Data used for our experiment was obtained from ‘Physionet: Fantasia database’ (Goldberger et al., 2000) and has been described in Iyengar et al. (1996). The experimental details is being succintly summarized here. Two groups of healthy adults: twenty young (age 21–34) and twenty elderly (age 68–81) with 10 males and females in each category participated in the study. All provided written consents and underwent blood count, biochemical analysis and electrocardiogram (ECG) tests. They were healthy, non-smokers with no medical problems and not under any medications and had normal exercise tolerance tests.