What is HRV (heart-rate variability), and what's a good number?
HRV (heart-rate variability) is the variation in time between consecutive heartbeats, measured in milliseconds. A higher HRV generally signals a well-recovered, adaptable nervous system, while a drop often means stress, fatigue or illness. There's no universal "good" number — HRV is highly individual, so what matters is your own baseline and trend over time.
What's a normal HRV?
HRV varies enormously by age, fitness and genetics — anywhere from the 20s to over 100 ms (RMSSD) can be normal. Because absolute values differ so much between people, the useful signal is relative: is your HRV trending up (better recovery) or down (accumulating stress) versus your own 30–60 day baseline?
How Vita uses HRV
Vita reads HRV from your Apple Watch or WHOOP and uses it — together with resting heart rate and sleep — to compute your daily Recovery score and factor into your Body Age. Instead of a raw number, you get a plain-language read on whether to train hard or rest today.
FAQ
Is a higher HRV always better?
Generally yes, relative to your own baseline — higher HRV reflects better recovery and autonomic balance. But compare against your own trend, not other people's numbers.
How do I measure HRV?
An Apple Watch or a WHOOP band measures it automatically, mostly overnight. Vita reads it from Apple Health or WHOOP — no manual input needed.
Why did my HRV drop?
Common causes: poor sleep, alcohol, hard training, stress or illness. A single low day isn't alarming; a sustained downward trend is worth acting on.