Aerobic Test Thread

  • Creator
  • #58738
    Steve House

    Here is the description straight from your training plans:

    The heart rate drift test is used to determine your Aerobic Threshold (AeT). It is more accurate than the nose-breathing test suggested elsewhere on the Uphill Athlete website, especially if you are aerobically deficient( The goal is to do the workout at what you think is aerobic intensity (below your AeT). You must exercise for an extended period—about one hour—and at a steady effort while recording heart rate and GPS data.Here is a video explaining how to do the test:

    Watch this video after you have completed the test to set up your HR zones:


    Outside: On a flat course (running)

    Inside: On a treadmill or stair machine

    Do not do this test on an uphill/downhill out-and-back course. During the first half you will be going uphill and therefore doing more work, meaning the pace-to-heart-rate ratio of the two halves will be very different.


    * A GPS-enabled watch
    * A chest strap heart rate monitor that pairs with your watch or phone (we recommend against using your watch’s built-in wrist heart rate monitor)
    * A TrainingPeaks account, ensuring that your watch is connected and communicating with the account. Uphill Athlete will upgrade your account to Premium to view all the data. The various metrics TrainingPeaks ( provides are invaluable to athletes and coaches, and we gladly pay our fee to them (we receive no price break or kickbacks).


    If you are going to be doing a lot of running in your training, do this test as a run. If you are primarily going to be hiking for your training, do this test as a hike on a treadmill or stair machine.


    This effort should feel easy and relaxed—a conversational pace. In other words, you should be able to carry on a conversation in full sentences.

    1.) Run on a flat course at what feels like an easy aerobic pace. (See above for more detail on the desired effort.) If you have a good idea of what your AeT is, then target that heart rate for the beginning of the test. If you have no idea about your target, then the MAF formula of 180-age is a great place to start.
    2.) Once your heart rate stabilizes for 2–3 minutes after at least a 15-minute warm-up, start the recording feature on your GPS watch.
    3.) Record for 60 minutes while doing your best to keep your heart rate close to that initial heart rate number.
    4.) Upload the data to TrainingPeaks.
    5.) Open the workout in TrainingPeaks and click the “Analyze” button. In the window to the right of your workout graph you will see Pa:Hr X.XX%. This decoupling metric compares the pace-to-heart-rate ratio of the first half of the workout to that of the second half. Note the number and skip ahead to “Reading the Results.”

    1.) Set the treadmill to approximately 3% if using a running gait and 15% if using a power hiking gait. Make sure that the treadmill will not automatically stop after 60min of activity.
    2.) Gradually build speed over the first 15 minutes until your heart rate stabilizes at what you feel is an easy aerobic effort for 2–3 minutes. (See above for more detail on the desired effort.) If you have a good idea of what your AeT is, then target that heart rate for the beginning of the test. Once you’ve dialed in the speed and grade, do not adjust them again during the test.
    3.) Now you are ready to begin the test: Run or hike continuously for 60 minutes at that speed/grade while recording your heart rate.
    4.) Upload the data to TrainingPeaks. Since GPS does not work indoors, the pace part of Pa:Hr will not be accurate. That is why it is so important that you hold the pace and grade constant once you start this test on a treadmill.
    5.) Open the workout in TrainingPeaks and click the “Analyze” button. You will see a graph of your heart rate, pace, and elevation. To calculate heart rate drift, select the first half of the test in the graph and note your average heart rate in the window to the right of the graph. Then do the same for the second half. Compare the two numbers to determine the percentage rise of your average heart rate.


    3–5 percent: You have determined your AeT heart rate, which was your starting heart rate for the test. Set that as the top of Zone 2 in your TrainingPeaks zones. Subtract 10 percent from this and set that as the top of your Zone 1.

    0–3percent: The workout was within your aerobic intensity zones, but you should do the test again at a starting heart rate that is 5 beats per minute (bpm) higher.

    >5 percent: Your initial heart rate/pace was above AeT. Redo the test using a lower starting heart rate. It may take several attempts to nail a decoupling that is slightly less than or equal to 5 percent.


    Keep in mind that your AeT is not fixed. It changes day to day based on your recovery state and overall fitness. The decoupling (heart rate drift) metric is a convenient means of ensuring your workouts are within your aerobic capacity, and it can be used as an occasional spot check on your AeT.

  • Moderator
    MarkPostle on #59053

    @anurag pw:hr is usually indicating power:heart rate ratio. Are you recording the workouts as Run or Hike?? As to the second part of your question I would start with the lower number for AeT and see how it goes for a few weeks.

    MarkPostle on #59054

    P.tenaerts You certainly can do it by a number of different methods if needed! What is your normal mode of training for mountaineering that gets your HR up into these zones??

    MarkPostle on #59055

    Bill- I would run another test at your leisure and maybe even start at 128 or so. Yes you can assume 125 in the meantime no problem. If your not new to this kind of training and not expecting dramatic movements in the AET you don’t need to check it again for at least 8-12 weeks. If you regularly use a treadmill or similar then its pretty easy to do a similar effort just to take a peek. We have a AnT test in the program about week 5 I think. You can of course run it sooner if you wish

    Anurag Doshi on #59056

    Mark, I was using the “run” outdoors but with the new Coros Vertix 2 watch.

    MarkPostle on #59057

    Anurag- I went in and resaved it as a hike instead of a run in TrainingPeaks and that swapped it to Pa:Hr ratio.

    Nate Emerson on #59061

    Hi Bill,
    Great questions.

    Estimating AeT HR: Yes, it’s probably ok to extrapolate a little bit if you are this close. Since you are comparing the first and second half of the test, I’m assuming that this was a treadmill run. If you were running outside, you’ll want to refer to the Pa:HR metric in TrainingPeaks for your 60min AeT Test.

    Retesting AeT: No need to do this too regularly. Every 8 weeks is adequate. More frequent testing is fine, since the test is really just at/above the top of Zone 2 if done correctly. As you mentioned, aerobic adaptations take time and many athletes might take 2-3 months to see appreciable adaptation. If you test indoors, note your pace/incline. Often athletes will see more adaptations in their AeT Pace than adaptations in their AeT HR.

    Anaerobic Threshold (AnT) Test: We have the AnT Test scheduled for the beginning of Week 5. Until then, all the running or hiking will be below Aerobic Threshold.

    Drift Test versus lactate testing: The Drift Test is definitely an easier option! Uphill Athlete has seen a high correlation to the results from lactate testing.

    Nate Emerson on #59063

    Hi Niv,
    We’ll test Anaerobic Threshold on Week 5. For now, we’ll focus on aerobic base exclusively and do all training below AeT HR.

    The mobility videos are in Vimeo. Vimeo probably won’t load correctly if your browser isn’t updated. Check to make sure that you’ve applied recent updates. We verified the links are working for Chrome and Safari.

    *For everyone looking closer at the Zones: Please don’t adjust “Threshold Heart Rate” in Training Peaks. We’ll update that with the Anaerobic (AnT) Threshold Test on Week 5

    Umer on #59072

    Hi Mark

    I did the AeT HR test on Friday with 138BPM as starting point; the difference was 1.4% (143/141).
    On Monday, I did the second AET HR test with 145BPM as starting point; the difference was 2.0% (149/146).

    Need your advice:
    BPM to be considered as AeT Threshold & Anaerobic Threshold?
    Should I run another AeT test soon?


    MarkPostle on #59075

    Umer- left a comment in your trainingpeaks file from Monday.

    Umer on #59076

    Dear Mark

    Thank you so much for the prompt feedback and guidance.

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