Struggling to pin down AeT and AnT | Uphill Athlete

Struggling to pin down AeT and AnT

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  • #15857

    Hi all,

    After a very unhealthy second half of 2018, I’m psyched to get fit and strong again in 2019.
    I’m trying to nail down best guesses for the key HR markers as a basis for training, but I’m struggling to get figures I have confidence with.

    I’m 34 years old, 180cm (5’11”) and currently weigh 83kg (183 lbs). I was 77-78kg mid last year. I like to run (done a 56km 2000 vert m ultra), previously rock climbed a lot (3 years ago, before breeding) and I love a bit of alpine climbing, but its not very often because I live in Australia.
    My current goals are getting fit for the spring (in Australia) trail running season (and dropping some kg in the process), and then really build up the rock again with the hope of joining a couple of mates on Lotus Flower Tower August 2020.

    I’ve got a small (170vm, 550′) hill near to my house, but its a 30min drive to get to a bigger hill (750m, 2500′). I’ve tried to get the AeT sorted on my local hill, and AnT on the bigger one.

    There’s a screen shot from TrainingPeaks attached. This was my effort this morning. Fluked it to get 30 mins of continuous uphill before the track dropped down briefly (killing of my mojo). I was pretty knackered by the end of 30 mins so feel like its a reasonable shot at getting my AnT. Average HR was 171.

    There’s another screen shot attached from a run when I tried for AeT twice up the same track. I’ve had several goes on my local hill trying to nail this down using the nose breathing limit technique. It’s tricky though, as I can do 10-15 mins at HR 166ish only nose breathing and feeling like I’m doing it quite comfortably. I am doing deep regular breaths, and it feels entirely sustainable.
    The reasons I doubt this is the correct AeT are because others here who are fitter have significantly lower AeT, and this would suggest a difference of only 5bpm between AeT and AnT, which is about 3%, which sounds like a stat for an elite athlete.

    If anyone has a bit more experience in gauging AeT and AnT from these tests, I’d be super appreciative if you could offer your opinions…

    – Mike

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    Anonymous on #15863

    To best gauge AeT using nose breathing, you want to make sure you precede the test with a very thorough, very gradual warm up. If you jump into it too soon, you’ll be able to still breathe through your nose, but lactate levels will be above your aerobic threshold.

    I don’t know why this is, but I’ve tested it with my lactate meter. If I ramp up too much too soon, I can still breathe through my nose with lactate around ~3. To avoid that, I would warm up very slowly for at least a half hour.

    This is important to get right. Training above your AeT without knowing it will create unwanted adaptations. Training below your AeT without knowing it has no disadvantages.

    I suspect your AnT is reasonably close given your description of the effort.

    Anonymous on #15866


    I agree with the points Scott made.

    The 30 min AnT test looks solid and I’d say 170 is prob a decent number to go with for the top of Z3. The AeT tests look to be only 9 min long so I think you might be able to do better with some other tests.

    Here are some thoughts:
    1) If you can run and have a relatively flat to gently rolling loop (not out and back) course you can run for an hour at what you think is AeT
    2)You can also do this test on treadmill or stair machine.

    Since you are using TP I suggest you use this article to help you dial in your AeT.

    As Scott said there’s no down side to training below AeT unintentionally. But, there can be some serious issues with training above AeT unintentionally.


    mjb on #15929

    Wow, two responses on the same day. Thank you to both Scotts for the super fast turn around time and your expert input!

    I had read in some threads about your experience with a good slow warming being required. I did wonder if that might be a factor (but didn’t think it would be that much).
    I went for a run on Monday morning (48hrs after the AnT test) and kept HR below 140 for the first 40mins (average 126) over undulating terrain around my local hill. Then very gradually built up the intensity heading up the hill, and it felt like the nose breathing limit was approx 150 bpm. I was focussing on experimenting around a bit more, not maintaining a constant level, so that might change. This would be about 13% lower than my AnT which seems a more reasonable difference

    I am intending to do this again ASAP, hoping to find a good steady state. I also suspect that I may not have been fully recovered from the AnT test (I could definitely feel some lactic in my legs), so that might even drop my AeT down a little more.

    In short the answer is to do a big, slow warm up.

    Thanks once again for your thoughts!

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