Dealing with Cardiac Drift in Z3 intervals

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  • #44854

    Hi guys,

    So, I started Z3 training lately. I have a short hill in my neighborhood (65m ascent, 1km). The hill is rather unsteady.

    I started with the recommended 3x8mins. Active recovery takes a little longer, since I need to hike down the hill.

    My AnT is 172. I try to stay at/below AnT. But I observe significant cardiac drift between the repetitions. I get slower from rep to rep when I just go by HR.

    How do you guys deal with that? Will I not get the intended Z3 stimulus?

    Best regards

    PS: Doing it on a treadmill is not an option

  • Inactive
    Anonymous on #44876

    How did you determine your Z3? Assuming it’s what you’ve been able to sustain for 30-45 min, I would start with shorter intervals. 4×4 min. is a good starting point. I’ve found that if you’ve been focusing on Z1/2 for a long period of time, you have to go quite hard to get up to AnT, and it’s easy to overshoot muscularly, so that it’s hard to sustain. You could use the same hill, but only do 4 min. at a time, and gradually work your way up it, or simply do repeats of one section of it. Also, what kind of warm up are you doing? Adding in 2-3×2 min. working up to AnT after your easy warm up can help your body switch gears. Good luck!

    Dada on #44887

    Hi Alison,

    Thx for your answer!

    Determined the AnT by a 40min all out last week: AnT decreased

    I can reach Ant without any problems. The first minute my legs burn, then my FT fibres are tired I guess and the solely the STs take over. It feels hard though.

    I started with 5x6min last week, then 2 times 4x9min, yesterday 9×5.50min. I observed cardiac drift everytime because I slowed down from rep to rep bc I was keeping my HR steady.

    My warmup: either cycling there for 30min in Z1 or running there in 20min in Z1. So far no higher intensity as warm up. Will incorporate your recommendation of higher intensity.

    Best regards

    Anonymous on #45077

    It sounds like you’re going too fast to start. Unless there’s a very big difference in the relative strength of your cardiovascular system versus your legs, your legs shouldn’t burn in Z3. That happens at higher intensities.

    Related to this is that there’s too much lag in heart rate to use it as a reliable measure of intensity over AeT within the first few minutes, especially on the first repetition. If you do some treadmill training, you’ll find that the first few reps at Z3 pace will feel much easier than you expect.

    It sounds to me like you’re trying to hit your Z3 HR too quickly, so to do so, you’re going too hard out of the gate. Then your legs get trashed, your pace slows in later reps, and your legs don’t have the power to tax your CV system into Z3. I suspect that’s why you’re seeing a stop in HR.

    Next time, start more conservatively and try to maintain a constant output per rep. Look for your HR to be in Z3 late in the first few intervals and sooner in the later ones.

    Dada on #50943

    Hi Allison & Scott,

    I still observe a similar issue but this time in ski mountaineering: Short excursion to Z3 leaves my HR highly elevated

    I would love if you could take a look at this question.

    Is there something I can do about that through training?

    Thank you very much

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