Split calculator

Your training zones

1. UT3 Fuel utilisation under 80% Continuous, easy. Long steady work. –
2. UT2 Basic oxygen utilisation 81–85% Continuous, low intensity. Building your base. –
3. UT1 Oxygen utilisation 86–90% Moderate, steady state. –
4. AT Anaerobic threshold 91–95% Hard, continuous or long intervals. –
5. TR Oxygen transport 96–100% Hard to very hard intervals. –
6. AC Anaerobic capacity 100%+ Very hard, short intervals. –

Tap a zone to pick it out. Percentages on the Split tab are of your best pace; on the Heart rate tab they're of your heart rate reserve.