Last updated: 3 October 2026
Reviewed by Jordan Morley, FA Level 2 Football Coach
Concept2 and British Rowing use a 5-zone system: UT2 (utility training 2, easy aerobic, 60-70% MHR), UT1 (70-80%), AT (anaerobic threshold, 80-87%), TR (threshold/race, 87-93%) and AN (anaerobic, 93-100%+). The zones are also expressed as percentages of 2K race pace split. Most rowing programmes recommend 70-80% of volume in UT2 with targeted AT and TR work. The system was developed by Rowing Canada and British Rowing and is used internationally.
- UT2, UT1, AT, TR, AN
- UT2 = easy aerobic (60-70% MHR)
- 70-80% of volume in UT2
- AT and TR zones for quality work
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British Rowing's UT2-to-AN zone system mirrors the heart-rate-zone approach used in running and cycling, but is built specifically around rowing's unique demand for both aerobic base and explosive power — most structured rowing programmes spend the majority of weekly volume in UT2 (easy, conversational) with only a small fraction at AT or AN intensity.
FAQ
What does UT2 mean in rowing training?
UT2 (Utilisation Training 2) is the easiest, most aerobic training zone — low intensity, long duration, forming the bulk of most rowers' weekly training volume.
How much training time should be spent in each zone?
Most endurance-focused rowing programmes follow a polarised approach: roughly 80% of volume in UT2/UT1 easy zones and only around 20% at AT (threshold) or AN (anaerobic) intensity.