Enter your Lactate Threshold Heart Rate (LTHR) to estimate training zones as simple percentages of your threshold. This anchors zones to your actual physiology.
Click here to learn how to perform a guided test to determine your Lactate Threshold.
| Zone | Purpose | % of LTHR | Target HR (bpm) |
|---|---|---|---|
| Zone 5 | Anaerobic | Above-threshold efforts, neuromuscular and glycolytic dominance. | >100% | — |
| Zone 4 | Threshold | Hard, sustained work near LTHR. | 95–100% | — |
| Zone 3 | Max Aerobic Function | Strong aerobic conditioning. | 89–95% | — |
| Zone 2 | Aerobic Capacity | Moderate aerobic development. | 80–89% | — |
| Zone 1 | Upregulation & Downregulation | Easy, recovery-oriented effort. | 65–80% | — |
These zones are simple percentages of your Lactate Threshold Heart Rate. Refine with RPE, pacing, and performance metrics.