Terms of Use

Effective September 10, 2026.

Informational use

These tools provide calculations and general reference information. They are not personalized training advice, medical advice, or a guarantee of race performance. Heart-rate formulas estimate zones; they do not determine a heart rate that is safe for you.

Accuracy and availability

We aim for accurate calculations, but input errors, rounding, changing records, and conditions outside this application can affect interpretation. Verify critical information with race organizers or governing bodies. The service is provided as available, without a guarantee of uninterrupted access or fitness for a particular purpose.

Responsible use

Use the tools lawfully and do not interfere with their operation. You remain responsible for how you use the results. Nothing in these terms limits rights or obligations that cannot be limited under applicable law.

These tools provide informational estimates, not personalized medical advice. Targets do not guarantee performance or safety. Consider your fitness, terrain, weather, altitude, and recovery. For health concerns, consult an appropriate healthcare professional.