A high heart rate isn't always bad. A low one isn't always good. What says far more about how well you recover: the variation between your heartbeats.
What is HRV exactly?
Your heart doesn't beat like a metronome. Between each beat there's a tiny variation — milliseconds. The bigger that variation, the better your autonomic nervous system responds to stress and recovery.
People with high HRV recover faster, sleep deeper and perform better under pressure. People with low HRV — especially when it suddenly drops — are often overtrained, ill or stressed.
How do you measure it?
Good sports watches (like the Pro X) measure HRV automatically during sleep. That's the best moment: your body is at rest and the measurement is consistent. One reading during the day says little — the pattern over weeks says everything.
What is a good HRV?
It varies enormously per person. A 25-year-old athlete might have HRV above 90 ms, while a healthy 50-year-old is fine with 35 ms. Don't compare with others — compare with yourself.
The Pro X shows your trend over 30 days. Does your HRV drop three days in a row while training load stays the same? Your body is saying: rest day.
How do you raise your HRV?
- Sleep 7–9 hours — by far the most important
- Limit alcohol — one beer drops HRV 10–20%
- Breathing exercises — 5 min of 4-7-8 breathing works immediately
- Train consistently but not maximally — 3× hard, 2× easy
- Eat earlier — not within 3 hours of sleep
HRV is not a magic number. It's a mirror. What you do with it is what matters.