Autonomic nervous system
DEAutonomes Nervensystem
The autonomic nervous system (ANS) runs all the things you do not consciously control: heart rate, blood pressure, digestion, breathing. It has two main branches. The sympathetic branch is your 'fight-or-flight' accelerator. The parasympathetic branch is your 'rest-and-digest' brake. A semi-independent third branch, the enteric nervous system, runs your gut. In longevity science, doctors gauge how well your ANS is working through HRV (heart-rate variability), baroreflex sensitivity, and how fast your heart rate recovers after exercise. That is because a poorly balanced ANS, stuck in chronic 'fight-or-flight' mode (dysautonomia), is tied to heart disease and faster biological aging.
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Sources
- Malik M, Bigger JT, Camm AJ, et al. (1996). Heart rate variability: Standards of measurement, physiological interpretation, and clinical use. Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology. European Heart Journaldoi:10.1093/oxfordjournals.eurheartj.a014868
- Errico JP, Ben-Azu B, Gargus M, et al. (2025). Sympathetic-parasympathetic system deregulation theory of aging. npj Agingdoi:10.1038/s41514-025-00293-2