Last updated: 3 October 2026
Reviewed by Jordan Morley, FA Level 2 Football Coach
Heart rate variability (HRV) measures the variation in milliseconds between successive heartbeats. Higher HRV generally indicates better recovery, lower stress and higher readiness to train hard. Lower HRV signals accumulated fatigue, illness or high stress. HRV is tracked daily by wearables like WHOOP and Garmin watches. Training should be lighter when HRV is suppressed and can be harder when HRV is elevated relative to your baseline. Individual baselines vary enormously — only your own trends matter, not comparisons to others.
- Variation between heartbeats in milliseconds
- Higher HRV = better recovery generally
- Lower HRV = fatigue, illness or stress signal
- Track daily trends, not absolute numbers
In practice
HRV measures the variation in time between consecutive heartbeats, and a higher HRV generally indicates a well-recovered, less stressed nervous system — many athletes now track morning HRV via wearables to decide whether to push a hard training session or prioritize recovery, since a notably suppressed HRV reading can signal accumulated fatigue, illness or poor sleep before any other symptom appears.
FAQ
What does a low HRV reading mean?
A lower-than-usual HRV often indicates the body is under stress — from poor sleep, illness, overtraining or life stress — and many athletes use it as a signal to scale back training intensity that day.
Is a higher HRV always better?
Generally yes, within an individual's own normal range — HRV is highly individual, so tracking trends relative to your own baseline matters more than comparing your absolute number to anyone else's.