Free tool , health
Find your heart rate training zones.
Most people train too hard on easy days and too easy on hard days. Zones fix that. Enter your age, and if you know it, your resting heart rate from your watch, and get five zones with a plain description of what each is for. Everything runs in your browser, nothing is saved or sent anywhere.
Uses the Karvonen method, which scales zones between your resting and estimated maximum heart rate (220 minus age), so two people the same age with different fitness get different zones. The formula max is an estimate, real max can vary by 10 or more beats either way.
The 80/20 idea in one paragraph
Endurance athletes at every level tend to improve fastest spending about 80 percent of training time in the easy zones, 1 and 2, and only 20 percent in the hard ones. Zone 2 feels almost too easy, you can hold a conversation, and that is the point. The common mistake is living in zone 3, hard enough to be tiring, not hard enough to force adaptation.
General fitness information, not medical advice. If you are new to exercise, over 40 with risk factors, or on heart or blood pressure medication that affects heart rate, talk to a doctor before training by these numbers.
See the apps we build →