The most useful indicator of your overall health
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Science & technology | Well informed
“Heart-rate variability” has been decades in the making
Illustration: Cristina Spanò
Jan 16th 2026|3 min read
Modern smart watches can measure all sorts of health indicators. Step counts and heart rates sit at the simpler end of the array, whereas VO2 max and blood-oxygen levels are of more interest to committed health nuts. But a category currently attracting particular attention is heart-rate variability (HRV).
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