Skip to content

Heart Rate Variability

  • When both the sympathetic nervous system and the parasympathetic nervous system are giving instructions to the heart it causes variability in the interval between heartbeats, which is a good thing.

  • When those systems are well balanced there is a lot of variability because they are both getting their way

  • Heat Rate Variability (HRV) measures the relative balance between the sympathetic and the parasympathetic systems. Performance Index, Performance Potential Index and HRV are used interchangeably.

  • The higher HRV (or the Performance Index) is, the more “ready” your body is to execute at a high level.

  • Since the autonomic nervous system organizes arousal in both the body and the brain, poor (lower) HRV has a negative effect on thinking and feeling and on how the body responds to stress.

  • An unusually low HRV Index results when the sympathetic and parasympathetic nervous systems are out of sync and may indicate a stress-based health vulnerability.