AeT Test via Heart Rate Drift

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  • #43208

    I’m in to the week 4 of my base phase, and I thought it would be a good time to test my AeT. I’ve been estimating it for this training cycle and honestly for all of my prior training efforts. This has been the first time I have been consistent enough in my training to warrant knowing the AeT with more specificity.

    I went in to the warm up shooting for 155, but I felt pretty solid as my Hr leveled out at 160 in the warm up. My Anaerobic Threshold test a few weeks ago came out to 176. The trail was supposed to be a nice flat, crushed rock path that ever so slightly trends uphill. I chose to run it straight rather than out and back just in case. Apparently I missed the notice the city is replacing a bridge so I had a little interruption/detour as I had to get around the bridge work. 10 minutes in to the test portion (25 min accounting for the 15 min warm up) you can see I had to redirect on some paths down in the park for roughly 10 minutes.

    All told, I felt great and thought I likely hit it on the head for the AeT at 160; a little higher than I thought…so I was feeling pleased to see results. But when I select the 60 minutes of the test I get a Pa:Hr of -3.57%?!? I presume 1 of 2 things is happening, my AeT is way higher than I thought…or the detour messed with the results.

    Any insights or info I can glean? Should I simply run the test again next week? Or can I read the tea leaves and infer my AeT? With my Lactate Threshold at 176, I have reservations thinking my AeT is much higher than 160.

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    legume on #43217

    Hi Bryden,

    Your run looked good until you had to detour at that bridge! I think that sudden change in pace is what is causing a poor read for the HR drift test. Unfortunately you just have to just retake the test I think. Finding your AeT is important enough that you should probably take a couple of tests anyway.

    Anonymous on #43227

    …or the detour messed with the results.

    Anonymous on #43228


    * Don’t worry about the gain. 40′ in six miles isn’t anything to worry about; and
    * Rather than a screenshot, make the next test workout public and post a link to it.

    bryden12 on #43401

    Thanks for the input folks. Second attempt: felt good in the warm up, but a little too good. I was shooting for 160 but my Hr at 15 minutes leveled out at 162 so I stuck with it. Pa:Hr came out at 5.81% for the last 60 minutes of the run. I think I know what that threshold feels like though. My HR seemed to be bouncing all over the place throughout the test, I just never could settle in to a rhythm. I’ll test again some time in the next few weeks and tone it back a few bpm.

    Link to the AeT workout:

    Anonymous on #43569

    “Bouncing all over the place”? It looks nice and steady to me. (Heart rates cannot stay constant.)

    Have you done an anaerobic test as well? (i.e. 30′ time trial)

    bryden12 on #43761

    Thanks again for the continued input, sorry for my delay I was out of touch last week.

    The “bouncing all over the place” was my impression every time I looked at my watch, HR seemed to never settle in. That is I’d see 165 at one moment, another it would be 160. The detoured AeT test the prior week felt much more in rhythm with less variability (apart from the clear impact of the detour)

    Here are my recent test attempts:
    6/16: Anaerobic TT (10 min warm up and 30 all out):
    7/1: AeT attempt 1 (detoured):
    7/8: AeT attempt 2:

    Anonymous on #43774

    I’d see 165 at one moment, another it would be 160.

    That sounds settled to me. It’s best to think of HR in 5-bpm “buckets”. Anything less than that is false precision IMO.

    Based on your tests, I think you can use: 175 for AnT HR; and 160 for AeT HR. (I would ignore the detour test and go by the Pa:HR of the second test.)

    With less than a 10% gap between thresholds (175 / 160 = 1.094), Z2 training will probably feel more fatiguing. As it does, you’ll want to shift more of your volume to Z1 (<= 145).

    bryden12 on #43778

    Thanks for the assistance and clarification. I’ll be moving forward with these thresholds with more confidence. I really appreciate the help.

    I believed I may be around that 10% AnT/AeT gap so I’ve been giving myself a little freedom to dip in to Z2 (145-159) on some hills here and there, but spending majority of my Z1 training around 135-140. I had 30 minutes in Z3 today and I’m feeling the difference in fatigue. Knowing my zones with more certainty has been such a helpful tool to interpret my fatigue and body’s response to a specific training effort. Still trying to get my head wrapped around the fatigue response from ME and strength workouts, seems that one will remain nebulous.

    Again, thanks for the help. Scott, would you recommend a custom training plan when I near the end of 20 weeks? I don’t have objectives on the calendar and I’m looking to continue to build my base without pushing the potential for overtraining. I’m not looking for high end coaching, but more clarification on how to build my time each week.

    Anonymous on #43817

    A custom plan is always an option, but so is repeating a training plan and modifying the loads. Training plans can be re-used indefinitely if you scale the load to your fitness at the time.

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