Zones are based on your heart rate, but each app has its own idea of where they start and end. Beth Skwarecki Beth Skwarecki Senior Health Editor Experience 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. Read Full Bio April 24, 2026 We may earn a commission from links on this page. Credit: Composite / Alisa Stern; Shutterstock / luckyraccoon Here are all the ways to find the right fitness wearable for you, and how to make the most of the data it can offer. “Zone 2” is the term the fitness world has (mostly) agreed upon to describe the low-intensity cardio most of us should be doing regularly . When you’re in zone 2, you’re working hard enough that you start breathing more heavily, but easy enough that you could hold a conversation while doing it. You stop a zone 2 session because your workout time is up, not because you’re too exhausted to continue.…