Heart Rate Drift, etc. | Uphill Athlete

Heart Rate Drift, etc.

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  • #38962

    Hi! Thanks for making these forums available, I’ve learned a ton just rifling through these.

    I was hoping to ask a question regarding heart rate drift and AeT. When I began reading the training bible that is Training for the Uphill Athlete I did the treadmill test (breathing through the nose) to determine the ballpark of my AeT. After reading some of the comments I began to doubt whether or not my AeT really was the 158bpm that I had calculated from the treadmill. I sort of put myself in the ADS category and then read that those individuals can potentially breathe through their noses above AeT. So I did the heart rate drift test this morning, as advised, on a relatively flat loop for about an hour. Training peaks calculated the Pa:Hr (according to the app on my phone) at 1.6% which hints that I was correct about my AeT? My question is, as the calculation is a simple ratio is it possible that I am above my AeT but simply running at a constant pace/HR so the ratio is good? Is it possible to be above AeT but still get a Pa:Hr below 5% ?

    It’s not that I don’t think it’s impossible for me to have this AeT, I just want to be sure I’m getting the most out of my training! Thanks so much for reading!

Posted In: Mountain Running

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    Anonymous on #38983

    The TP Pa:Hr algorithm is sophisticated enough that it senses the drift and compares the first and second halves of the run to give you the percentage of drift overall. It is a ratio of pace to heart rate. If done on the flats it does not depend on a steady pace or steady heart rate.

    1.6% would indicate that you were under your AeT for that run.


    Anonymous on #39181

    The only thing to be cautious of is if you were going at a pace well above your aerobic threshold and close to your anaerobic. The way to confirm this is to do an anaerobic threshold test and confirm the difference.

    The important difference between the two tests are:
    * With the anaerobic threshold test, due to the intensity and duration, your heart cannot go higher. It’s the highest average heart rate that you can maintain for 30-45 minutes (if you’re new to training);
    * With the aerobic threshold test, your heart rate could go higher but doesn’t. The fact that it could go higher, but doesn’t indicates that you’re operating at or below your aerobic threshold.

    alicechandler4 on #39254

    Great, thanks! I will attempt the AnT test and see where I’m at. I definitely could have run faster for that hour, it felt relatively easy so I’m inclined to think I was at AeT.

    One more question.. My pace at this assumed AeT was 10:36/mile and I’d really like to get a little faster. Will continuing to train at or just under AeT alone achieve this or does an increase in intensity need to be applied? From reading articles and TFTUA I’ve seen some snippets that say pace should speed up eventually. I know the 10% test is helpful for WHEN to begin intensity training but I was just curious if it can be achieved through AeT training only?


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