Very high heart rate on downhills

  • Creator
  • #43506


    I’m currently working on correcting ADS and have made some progress recently. AeT has moved up 5 BPM and pace has increased from 9.5 KPH to 10.6 KPH.

    With this, and the lifting of travel restrictions here in Scotland I have been getting out to the hills.

    I can now comfortably hike uphill at my Aerobic Threshold – it’s slow going, there’s no running involved and it takes 1.5 hours to climb a VK but it’s a start. However on technical downhills and grassy descent sat. -15% grade something wierd happens.

    Despite going slower than my AeT pace (8.5-9 KPH) my heart rate will jump to pretty close to my LTHR. My muscles won’t hurt, and my breathing will be as it was on the climb. In this case RPE seems wildly disconnected from heart rate. Even when walking down my heart rate is still higher than AeT. When I get to the bottom and start a climb I can again easily climb at AeT. What gives? Note, on roads I can easily run fast downhill under AeT

    I’m loath to miss out on a summer of mountain running fun and the associated neuromuscular training as I need be better at reading technical terrain to move faster in races, and the time I have ready access to technical mountain terrain is limited until September.

    Additionally, I would like to race (long 20 mile race on a flat trail) and am planning to prepare for that by doing 5% volume high intensity for 4-6 weeks beforehand assuming that I will still be able to improve my aerobic capacity slightly during that phase, even if the AeT heart rate doesn’t budge.
    To prepare for the high intensity, can I do strides a few times a week or will that curtail progress with ADS?

Posted In: Mountain Running

  • Participant
    briguy on #43549

    To get the obvious question out of the way, what are using to track your HR? If it’s onboard optical HR from the watch itself then that is probably your culprit. They are especially susceptible to cadence being read instead of BPM. And on a big descent there would be a lot of bounce introduced causing the problem to exacerbate.

    If it’s a chest strap, then something else is going on.

    Paul.Williams on #43556

    Yeah, I am always using a chest strap to track heart rate.

    briguy on #43557

    Okay, that’s good. I can only offer anecdotal suggestions as I have seen on super long endurance runs in the mountains where, when fatigued, even going downhill will spike my HR. Especially a technical downhill, or a particularly steep downhill. I always attributed it to fatigue.

    Anonymous on #43578


    I can now comfortably hike uphill at my Aerobic Threshold – it’s slow going, there’s no running involved…

    That’s normal. Very few humans can run uphill at AeT, even after years of training. (They call the sport “mountain running” because it’s easier to sell than “hiking races”. 🙂 )

    I’m not sure about the elevated heart rate on descents. Are you trying to go at AeT pace or just casually descending? The eccentric loading on the legs is severe when going downhill, but heart rate is usually lower.

    r.j.hammond345 on #43659

    May I enquire as to the manufacturer of your chest strap? The reason I ask is that what you are describing is similar to what happens with my Suunto chest strap. It occurred intermittently after 60/70 days of use, then persistently after about 100.

    I bought a new strap to use while warrantying the duff one and low and behold; after 60+ days of use, the first instance of rogue readings.

    It only goes peculiar on downhills, and results in a reading about 30 bpm above the actual (I know this because I wore an old school monitor and strap at the same time to check).

    If you have already tried a different monitor, kindly disregard.

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