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Heart Rate Variability
The variation between your heartbeats, and what the research says it reveals about recovery.
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The ScienceWhat is heart rate variability? A complete guide to HRV
A heart that changes its rhythm slightly with every beat is a healthy heart. One that beats like a metronome is a heart under stress.
Heart HealthHRV by age and sex: normal ranges explained
Your HRV changes as you get older, and it differs between men and women. There is no single perfect number that works for everyone.
The ScienceHow the HLTH Band measures HRV, and what our accuracy study found
A number that does not reflect what is actually happening in your nervous system is worse than no number at all.
The ScienceHow the HLTH Band measures HRV continuously
A morning check tells you how you recovered overnight. It tells you nothing about the rest of your day.
Heart HealthLow HRV: what it means, why it happens, and what to do
A low reading is almost always temporary, and it almost always has a simple explanation. Here is how to tell the routine from the worth-checking.
The ScienceHLTH Band: science and clinical accuracy
Most wearable companies lead with marketing. This page documents how the band was tested, what the numbers showed, and where the limits are.
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