Heart-rate zone calculator
Enter your max heart rate to see the three simple bands TrailFree uses to guide effort: easy, tempo and intervals. If you do not know your max, an age estimate gets you close enough to start.
The three bands, and why so few
Most endurance training only needs three efforts, so that is all the trainer uses. Keeping it simple means the numbers guide you instead of ruling you.
- Long / easy, under about 70% of max. Conversational. This is where most of your time should go.
- Tempo, roughly 78 to 87%. Comfortably hard, the pace you could hold for a long effort.
- Intervals, above about 88%. Short, hard, with full recoveries.
A percentage of max heart rate is the simple field version of training intensity. It is not perfect, but it is honest and it travels well without a lab. If you have a chest strap, the app shows live zones during a session; without one, the words alone still guide you.
About the estimate. From age we use max ≈ 208 − 0.7 × age. It is only a rule of thumb, and real people vary by ten beats or more, so a max from a hard effort or a strap is always better.