Heart rate slows during exercise

I have noticed that when doing my cardio, which is basically 30 minutes of Cross Country module on a stationary bike, then I move to the treadmill, and do a module that will keep my heart rate at 75-80% of max for an hour. I have noticed that when I'm doing the heart rate module, that about half way into the routine, my heart rate will drop perhaps by 10% or so, and the treadmill will elevate to keep my heart rate up to the level I've asked it to be. For me, it's around 120 bpm, and my heart rate will drop to 110-113 and stay there until the treadmill elevates.

Remember, I've been at the 120-125 heart rate for about 30 minutes before the rate drops, so it isn't just that I'm "coming down" from the stationary bike,, I don't think. Any ideas as to what's going on?

Replies

  • hazleyes81
    hazleyes81 Posts: 296 Member
    How are you getting your heart rate measurements? If you're using the machines computers and sensors, they just may not be accurate so you're getting a different reading from the bike to the treadmill.
  • Azdak
    Azdak Posts: 8,281 Member
    The workload on the treadmill is not high enough to keep your HR at the programmed level. Because your HR is elevated from the bike, the treadmill does not change the workload at first. Eventually, your HR lowers to match the treadmill workload. When the treadmill senses that, it increases elevation to get you back into the programmed range.
  • oeagleo
    oeagleo Posts: 70 Member
    Thanks to those who answered, it makes sense, that because of the sustained higher rate, that the demand isn't as great, but what threw me off was the length of time for my body to get used to the new "demand"..

    In answer as to how I'm getting my heartrate, I use a Suunto Ambit 2, with a chest strap. I've found it pretty accurate, and consistent, and, surprisingly, it's close to the treadmills rate when I actually hold on to the little heart rate parts of the handle. I still trust the Suunto most though, I use it for my bicycle rides as it also has a built in GPS that will show my track when I do ride the bike. I also use SportTracks, which will give me LOTS of data, including a map, weather, wind direction, etc for my rides.

    Now, if it would just warm up a bit... *sigh*