As an athlete you are able to set your Heart Rate zones and enter your max HR.

To set the HR Zones click on your profile in the top right corner and then go to Settings when you log in on the web.

By default the 5 zones are set to:

Zone 1: 50 – 60%
Zone 2: 60 – 70%
Zone 3: 70 – 80%
Zone 4: 80 – 90%
Zone 5: 90 – 100%