HRV
The stress resilience metric. Heart rate variability (HRV) measures the variation in time between heartbeats. Counterintuitively, MORE variation is better—it indicates your heart can adapt quickly to demands. HRV reflects vagal tone and autonomic nervous system balance. Used by athletes for recovery tracking and increasingly recognized as a general health biomarker.
What HRV Reveals
Recovery Status
Low HRV = still recovering. High HRV = ready for stress. Training readiness.
Stress Load
Chronic stress suppresses HRV. Early warning sign. Both physical and mental stress.
Sleep Quality
HRV rises during restorative sleep. Tracks sleep quality. Morning measurement.
Autonomic Balance
Sympathetic vs parasympathetic. Balance is key. Vagal tone indicator.
Illness Prediction
HRV often drops before illness. Early warning system. Immune demand.
Aging
HRV declines with age. Higher HRV associated with longevity. Biological age marker.
What Affects HRV
Increases HRV
- • Good sleep
- • Regular exercise (not overtraining)
- • Meditation and relaxation
- • Proper nutrition
- • Social connection
- • Nature exposure
Decreases HRV
- • Poor sleep
- • Chronic stress
- • Alcohol
- • Illness/infection
- • Overtraining
- • Dehydration
How to Measure HRV
Wearables
Whoop, Oura Ring, Apple Watch, Garmin. Continuous tracking. Sleep-based.
Chest Straps
More accurate than optical. Polar H10 gold standard. Morning measurements.
Apps
Elite HRV, HRV4Training. Use camera or chest strap. Trends over time.
Important: Track YOUR trend over time. Absolute numbers vary hugely between individuals. Compare to your own baseline, not others.