The autonomic nervous system controls involuntary body functions, including heart rhythm, breathing, and digestion.
Two branches of the ANS:
Sympathetic nervous system (“fight or flight”):
- Activated during stress, danger, or physical exertion
- Increases heart rate
- Reduces heart rate variability
- Prepares the body for action
Parasympathetic nervous system (“rest and digest”):
- Activated during rest and relaxation
- Decreases heart rate
- Increases heart rate variability
- Promotes recovery and rest
ANS balance:
- A healthy body maintains a dynamic balance between the sympathetic and parasympathetic systems.
- HRV analysis makes it possible to assess this balance.
- Impaired balance may indicate stress, fatigue, or disease.