Central Frequency of Low Frequency Component of HRV Estimates Sympathetic Activity During Dynamic Exercise, Standing and Paced Breathing Maneuvers

In 25 healthy subjects we assessed the effects of the maneuvers supine position (S), dynamic exercise (DE), standing (ST), controlled breathing (CB) and DE recovery (DER) on the time-courses of' central frequencies and powers of the low and high frequency components of RR ( CF LF RR , pLF RR ' pHF RR ), systolic ( CF LFsp,pLF sp ) and diastolic ( CF LF DP , pLF DP ) pressures, estimated by a time-frequency distribution, and on the pLF RR /pHF RR and CF LF RR /pHF RR ratios. Relative to S, significant mean values changes (p