Fitness trackers and smart watches are widely popular wearable devices that measure several types of health metrics, including step count, calories burned, sleep quality, Vo2 max and heart rate. As a ...

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Here’s what HRV is, how it works and what can cause it to rise or fall.

You'd be forgiven for thinking of a well-known caffeine tablet which was big when I was a university student, but despite the ...

Fitness trackers give us unprecedented information about our health, especially when it comes to our hearts. Doctors explain ...

Beth Skwarecki is Lifehacker’s Senior Health Editor, and holds certifications as a personal trainer and weightlifting coach. She has been writing about health for over 10 years. December 4, 2025 Add ...