HRV, heart rate variability, is the small changes in time between each heartbeat. It shows how well your body can handle stress and recover. A higher HRV usually means you are more relaxed and recovered.
How to read it
- HRV is personal. Compare it with your own baseline, not with other people’s numbers.
- A value well below your normal often follows hard training, poor sleep, illness, alcohol or stress.
- Single readings jump around. The trend over weeks is what tells you how you are adapting.
Where your number comes from
Apple Watch measures HRV in the background and during Breathe sessions, in milliseconds, and saves it in Apple Health. Kiiro reads those values and shows the trend, next to your resting heart rate and VO2 max.
More: What is a good HRV on Apple Watch?
Related terms
- Resting heart rate: Resting heart rate is the number of times your heart beats in one minute when you are calm and not moving. A lower value usually means a fitter heart.
- VO2 max: VO2 max is the amount of oxygen your body can use when you exercise your hardest. It shows how fit your heart and lungs are.
- Load balance and status: Load balance compares your current training load with your long-term fitness. Your status, from Undertrained to Overtrained, is the one-word version of it.
