[lorenzo.riano]

Hi all,

A bit of my background: I’ve been running ultras for a few years and I’ve spent a long time doing long runs in and out the mountains. I have a good feeling about my running body, my pace and my effort levels.

Last week I’ve done the AeT test using the HR drift test. I’ve done the test according to protocol and on a track. I settled on a pace that was comfortably hard and went round and round for 1h after warmup. My average HR came up at 151 with a 7:57 pace and a decoupling of 1:55%. Great, these are numbers that by and large I expected.

Yesterday I did the AnT test by going as hard as I could around the same track for about 45 minutes. The result is a HR of 162 with a pace of 7:07. The pace was surprisingly high, and the HR was spot on what my Garmin Fenix says is my lactate threshold. I honestly thought the average HR for AnT would be higher, but whatever.

Now the weird thing: the Pa:Hr was 4.97%, that is within the number for Aerobic threshold!

There is no way that pace and HR is my AeT, it was too hard, I was breathing hard and would not have sustained for long.

So, how to interpret these results?

Topic

[Jared Casper]

Jared Casper on April 23, 2020 at 11:08 pm #40842

The reply from Scott Semple in this thread: https://uphillathlete.com/forums/topic/heart-rate-drift-confusion/ might provide some insight.

[lorenzo.riano]

lorenzo.riano on April 24, 2020 at 11:52 am #40865

Thanks Jared for the link! I see Scott’s point and it makes sense, but I’m not sure it applies to my test. Two years ago, during an all out half marathon, I have empirically measured my max HR to be around 178. So there’s plenty of room for the AnT test HR of 162 to grow.

In summary I think both the AeT (151) and AnT (162) are very close to reality, just based on my rate of perceived exertion, which is not perfect but not even out of whack given my experience.

My question then remains: why didn’t I observe cardiac drift during the AnT test?

Thanks again for the responses!

[Anonymous]

Anonymous on April 27, 2020 at 12:38 pm #40947

* Unless you gradually ramped up to your maximum heart rate in the first 12-20′ of the half-marathon, it won’t define your max heart rate. Maybe I’m wrong, but I think the duration is too long. Double-check it with a lab test if you’re interested (but max HR isn’t much use for training).

* Heart rate drift will occur at all intensities. HR is a global stress measurement. Training intensity is only one type of stress that is included, along with heat, dehydration, muscle damage, work stress, relationship stress, etc. As the length of any event increases, heart rate relative to pace will rise.

* AeT HR is estimated as a certain amount of drift (<5%) where more is possible with higher intensity. AnT HR may have less drift because greater drift isn't possible. With AeT, more drift is possible, but doesn't happen. With AnT, more drift is not possible because more intensity (for the duration) is not possible.

* You may even be able to conclude that if you had a 5% drift during the AnT test that you could have gone harder (and seen less drift).

I hope that makes sense.

[lorenzo.riano]

lorenzo.riano on April 30, 2020 at 8:48 pm #41074

Hi Scott,

thanks for the reply. It kind of makes sense, but still leaves me buzzing. From what you are saying it looks like HR drift seldom happens, and it’s hard to observe at high intensities. If so, isn’t it hard to use it as test for the AeT?

Regarding the AnT test, maybe I could have gone a bit harder, although I’m not really sure. And I know the max HR is not easy to quantify, but I also know that not so long ago I hit ~180, so there’s plenty of room from the 162 I observed in my AnT. Does that mean that I could have gone a lot harder for (gasp!) 45 minutes?

The reasons I’m stressing about these values is that the AeT is very useful for your training programs, and the AnT is very useful to calculate TSS and everything else in TrainingPeaks. Or are they? 🙂

[Anonymous]

Anonymous on May 1, 2020 at 1:30 pm #41083

Sorry for the confusion. Hopefully this helps:

* In a good AnT test, HR doesn’t show a lot of drift because it can’t.
* In a good AeT test, HR could show a lot of drift but doesn’t.

…not so long ago I hit ~180, so there’s plenty of room from the 162 I observed in my AnT. Does that mean that I could have gone a lot harder for (gasp!) 45 minutes?

Not necessarily. Having AnT HR at 90% of maximum is decently high. If 180 is indeed your max, then it makes sense for AnT to be at 160-165.

The reasons I’m stressing about these values is that the AeT is very useful for your training programs, and the AnT is very useful to calculate TSS and everything else in TrainingPeaks. Or are they?

Correct, but don’t stress about it. Training by heart rate is the best intensity gauge mountain athletes have (because of varying terrain), but it’s fudgy at best. It’s better to think of HR intensities in 5-BPM buckets rather than with single-digit precision. (Because single-digit precision doesn’t exist with heart rate training.)

[lorenzo.riano]

lorenzo.riano on May 3, 2020 at 9:27 pm #41117

Makes sense Scott, thanks for the reply!