Fig. 2.

Correlation of body fat percentage and heart rate variability during paced breathing. Linear regression for percent body fat measured by dual x-ray absorptiometric (DEXA) whole body scanning and heart rate variability low frequency/high frequency power ratio (LF/HF) computed from fast Fourier transform analysis of the electrocardiogram RR intervals in normalized units measured during paced breathing at 0.2 Hz for eight healthy 18–20 year-old African-American male university students studied twice (n=16). Pearson's correlation coefficient for controlled paced breathing at 0.2 Hz was not significant (r=−0.34).