HR "explodes" in uphill after a little downhill

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  • #42016

    Hi guys,

    I noticed something weird lately. I climb a mountain at let’s say at 140 bpm (which is below AeT). I rest at the top and then start going down. After 20 minutes, there was a slight uphill part again. Then my heartrate “explodes” and shoots to 155-160. I slow down to half of my uphill pace but still can’t control my heartrate. RPE is also very high (uphill before 4 / uphill after downhill 7). This happened twice lately.

    Why is that? And how can I fix this?

    Best regards

  • Inactive
    Anonymous on #42044


    I’m not 100% sure but I have a couple of ideas that might explain what you are noticing.

    You mention that you have “climbed a mountain” prior to seeing this. I assume then that you have been going for several hours. It’s quite likely then that you have accumulated significant fatigue in your “uphill” muscles. So much so that when you start back up hill after a descent those main uphill propulsive muscle groups are prefatigued and so respond poorly to the demand os going up at a normal PE.

    The second thing, which is also likely is that going downhill uses your leg muscles in a very different way than when they were carrying you up. Gravity is doing most the work on the way down and your muscles primarily resisting gravity using eccentric contractions. When you sudden switch to going up during along descent it is as if you are jumping off the couch with no warm up and trying to go up at the same pace as before but with no warm up.

    Other than more aerobic base training I can not think of a way to improve this.


    Dada on #44855

    I was thinking about that phenomenon today during my Z3 intervals. I ran a little hill (55m) 9 times and hiked down as active recovery. What I observed:

    I was hiking down, reached the bottom, turned around and the first let’s say one minute my legs burned. After the minute the burn was gone.

    My hypothesis is that my FT fibres are either recovered or recruited (by the force impact of the donwhill hike -> central governor theory). So, when I turn around and run/walk uphill again, the FT muscles are still recruited which stresses my cardiac system and results in the leg burn.
    Then after the minute (or couple minutes when intensity is higher) the FT fibres are either exhausted, or the central governor is realizing that the FT fibres don’t need ro be recruited.

    What do you think?

    Best regards

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