What is Heart Rate Variability (HRV)?
What is HRV and How to Use It for Training
Heart Rate Variability (HRV) is a measure of how much time varies between your heartbeats.
Contrary to what most people think, a healthy heart doesn’t beat like a metronome. A little “wiggle” between beats is a good thing—it shows your body is flexible and ready to adapt.
Higher HRV = your body is more recovered and resilient.
Lower HRV = your body is under more stress (training, lack of sleep, poor nutrition, illness, or life stress).
Why it matters for training
HRV acts like a window into your recovery system. It can help you decide if today’s run or lifting session should be:
Hard (intervals, long runs, heavy lifting)
Moderate (steady miles, accessory lifts)
Easy (mobility, light jog, technique work, or even rest)
How to use it
Track daily, not just once in a while. HRV only makes sense as a trend over time.
Look for patterns, not single numbers. One bad day isn’t a problem, but if your HRV is trending down for 3+ days, your recovery isn’t keeping up.
Match effort to readiness. If HRV is normal/high, push harder. If it’s low, scale intensity—even if you still train.
Don’t obsess. HRV is one tool. Combine it with how you actually feel, your sleep, and your training plan.
Bottom line
HRV helps runners and lifters train smarter. Think of it as an early warning system—letting you know when your body is primed for hard work and when it might need a lighter touch.