Flat vs. Hills Intervals

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  • #10313
    Daniel Sedlacek

    Hello, all more experienced guys!

    After more than a year of consistent and structured base training (mountain running, skitouring, never on flats), I decided to incorporate 1x per week interval training (AeT and AnT are within 10%) with 4mins intervals. I began with them on the athletic track, and my objective and subjective observations are:
    1)I can hardly elevate my HR above my AeT
    2)When I do, perceived exertion is really high, but I barely get above AnT
    3)I almost always have a pain in my belly (on the side, classic)
    4)I find it extremely boring, which is in combination with the perceived exertion and all the pain not very good for motivation to another interval session.

    Then I tried uphill interval training and my observations:
    1)I can easily get above my AnT
    2)Perceived exertion is also really high, I breathe like a machine, but I somehow enjoy it and it feels more natural
    3)No belly pain
    4)I find it super interesting and kind of looking forward to the next session

    So my question is, is there any significant training benefit for me to do flat intervals over hills? I found some articles on PubMed, which shows improvement of performance in both, sometimes better improvement with flat intervals (which make sense, if the testing track is 800m flat running). I never run on flat, so for me, uphill performance in mountains is what really counts.

    Thank you for your answers, I’m also interested in the explanation (metabolic differences, different use of slow/fast twitch fibers) between these two types of intervals.


Posted In: Mountain Running

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    Anonymous on #10316

    I don’t think there’s any benefit of flat intervals over hill intervals if your sport is an uphill one. On the contrary, judging by your abdominal pain, there could be a big disadvantage.

    Flat running demands a more open hip angle, so it sounds like maybe you over-extended a hip flexor. That’s just a guess though. You should go to a sport-centric physiotherapist to confirm.

    Anonymous on #10324


    Scott is correct about the uphill vs flat. I always encourage athletes to do their higher intensity work on a sport specific way. For you this means up hill. If your sport was road racing then flat intervals would make sense. For all mountain athletes it should be up hill. Hiking with a heavy pack for mountaineers and running or ski simulation bounding and striding for skimo racers. Take a look at this: https://uphillathlete.com/skimo-striding-and-bounding-technique/

    As for the side pain: It sounds like a classic “side ache” or “stitch” that runners often get and probably nothing serious to worry about.


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