The lactate threshold (LT) is one of the most important physiological markers for endurance athletes. It refers to the exercise intensity at which lactate begins to accumulate rapidly in the blood, leading to fatigue. Training close to this threshold can significantly improve endurance and performance, especially in long-distance running, cycling, and triathlon.
This calculator provides an estimate of your lactate threshold heart rate (HRLT) based on your maximum heart rate. While laboratory testing with blood samples provides the most accurate measurement, this estimation is widely used by athletes and coaches for practical training purposes.
Unlike VO₂ max, which defines your maximum aerobic potential, lactate threshold represents how efficiently you can use that capacity during real training and racing. Improving your LT allows you to run, ride, or swim at a higher percentage of your VO₂ max without fatigue, making it a key predictor of endurance performance.
| Category | LT (% of HRmax) |
|---|---|
| Beginner | 75–80% |
| Intermediate | 80–85% |
| Advanced | 85–90% |
| Elite | >90% |
Elite athletes are known for their exceptionally high lactate thresholds, often allowing them to sustain speeds that would overwhelm others. Here are some reported values:
| Athlete | LT (% of HRmax) | Notes |
|---|---|---|
| Eliud Kipchoge | ~90% | Marathon world record holder |
| Mo Farah | ~89% | Olympic 5K/10K champion |
| Paula Radcliffe | ~88–90% | Women’s marathon legend |
| Haile Gebrselassie | ~89% | Multiple world records |
| Jan Frodeno | ~90% | Olympic & Ironman champion |
| Chrissie Wellington | ~89% | Ironman world champion |
By improving your lactate threshold through structured training, you can delay fatigue and race stronger, whether in running, cycling, or triathlon.