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# What is your preferred method of testing anaerobic threshold?
- URL: https://www.scottsemple.com/what-is-your-preferred-method-of-testing-anaerobic-threshold/
- Published: 2022-04-27T19:04:00.000Z
- Updated: 2025-05-03T19:01:42.000Z
- Description: "I have been getting frustrated using AeT and thought I was just doing something wrong/not reading the data correctly... If not aerobic threshold, what is your preferred method of testing anaerobic threshold?"
- Author: Scott Semple
- Tags: Tools, Lactate Testing

Oliver asked:

> I have been getting frustrated using aerobic threshold and thought I was just doing something wrong/not reading the data correctly...

Yes, **aerobic threshold can be confusing**. It *is* the most important threshold, but there's too much kung-fu interpretation and explanation that goes on. For my own training, I would prioritize it, but for coaching, I would use anaerobic threshold. You can get 90% of the way there using some simpler rules of thumb.

> What is your preferred method of testing anaerobic threshold?

I prefer using **a \~4 mM lactate test on a calibrated treadmill at a sport-specific incline**, but that comes with some important caveats:

1. **Know that \~4 mM is only a *proxy*** for anaerobic threshold. It's not worth pinning it down precisely, \~4 mM will be close enough, and you can test it with less fatigue than a field or lab test;
2. **The treadmill needs to be calibrated** to get accurate data because most brands' treadmill accuracy is horrible. The one brand I would trust is a Woodway (but they're crazy expensive;)
3. The treadmill test will give you a pace and heart rate for AnT. Use the pace as the benchmark for constant-grade training (i.e. treadmill, flat road, etc). Use the heart rate as the benchmark for variable terrain; and
4. For road runners, I would test with a 1-2% incline (depending on the pace) to compensate for the lack of wind resistance. **For mountain athletes, use a 20-25% incline depending on the event they're training for.** For skimo, 25%.

**My second choice is the** [**30-minute Friel field test**](https://joefrieltraining.com/determining-your-lthr/?ref=scottsemple.com)**.** (The tests are virtually the same.) In order to not force the pace, a field test should be done alone and *not on a treadmill*. Social pressure will force the pace, and it's too easy to do the same thing on a treadmill.