[depeyster]

I really like the DIY Anaerobic Threshold Test because it is a direct measure of maximum output for a given period of time (in this case 30-60 minutes). Unlike gas exchange or blood lactate it’s at the level where the rubber sole meets the trail.

If cost, convenience, practicality, and safety were not a concern, it dawned on me yesterday as I was doing my long hike, that I ought to be able to conceive of something similar for AeT.

In his article on ADS, Scott Johnston wrote:

. . . if you’re training for an event over 3 to 4 hours in length, like a big alpine or mountaineering climb or an ultra-distance race, then the basic aerobic training is the event-specific training and the base training all rolled into one. That’s because the intensity you compete or climb at—your race pace or event-specific speed—is your aerobic threshold. In these longer events, your aerobic capacity is a direct measure of your event-specific endurance.

So, I did a thought experiment. Suppose I had a treadmill with no time limit (in real life I only have access to treadmills in commercial gyms where the maximum duration is either 30 or 60 minutes). My AeT pace would be my maximum sustainable pace of x minutes, where x might depend on my objective.

When you read the journal articles, they sometimes use time-to-exhaustion (TTE) measures. The DIY AnT test is a variant of a TTE test. In the AnT test, pace is held constant and average HR is measured.

The procedure:

1. After a rest day, pick an HR as a candidate for your AeT value.
2. Warm up on an inclined treadmill for 15-20 minutes until you are at your AeT HR minus 5 (to account for subsequent drift).
3. Stay at the incline and pace attained at the end of step 2 until you reach exhaustion (i.e., you are unable to continue).
4. Record the TTE and the average HR (both measured from the end of the warmup to the test’s end).
5. If TTE> 3-4 hours, then you were at or below your AeT.

That’s the thought experiment.

It left me with some questions.

1. Wouldn’t it be better to run the test for 8-10 hours or even longer, if you wanted to be able to spend long days in the mountains?
2. If, in the real world, you had to stop and restart the treadmill every 60 minutes, would that distort the results appreciably?
3. Why not chart TTE at a series of intensities and graph them? The AnT is TTE(.5-1h). The AeT is TTE(3-4h). Right now ADS is defined as a >10% gap between AnT and AeT. Seeing the shape of individual TTE curves might shed light on previously unknown relationships.

Topic