Heart rate declines during exercise rather than increasing

[CMKOfromAZ]

Why does my heart rate decline rather than increase when running?  I have started to use a heart rate monitor during exersise to ensure that I am working in an optimal cardio range. Instead of finding optimal cardio rate, I have had bizarre results. My resting heart rate is 88 BPM, but when I start jogging on the treadmill it quickly drops to 61 BPM. After running for a few minutes and feeling short of breath and tired, my heart rate is still only 63 BPM. However when I stop exercising, my heart rate quickly (in about 30 seconds) jumps to over 150 BPM and will stay elevated for a few minutes, but then my heart rate will steadily decline again when I start running again (declining about 1 BPM into the 115 range). While my heart rate never drops back below 100 after my first "rest", I can repeat this inverse response to exertion indefinately (stop running - heart rate jumps up; start running - heart rate steadily declines). How can this be possible?

[CMKOfromAZ]

I've gotten my new, coded chest-strap and have tested that out.  My readings are far more normal, so I am sure that my old transmitter must have had a weak battery.

I'm still noticing a quick drop (10-20 bpm) when I start exercising, but then my heart rate steadily climbs with exertion and steadily declines when I reduce my effort, as expected.

I will make an appointment to see a doctor and ask again about the shortness of breath and high resting heart rate, especially if they persist despite my doing regular cardio exercise... but now I feel better about continuing to exercise regularly while I wait for a doctors appointment.  I was so freaked out by the crazy readings that I was concidering discontinuing my exercise program.

Thanks for the excellent advice that it was just a faulty transmitter!

[Bromley]

I agree with these opinions. Watch for other symptoms. If you experience shortness of breath and erratic heart beats, you should consider seeing the doc and getting tested.

[itdood]

Hi, if you've confirmed your HR is going down for sure, you should call your doctor and get an appointment for a stress test.  

The only thing that I can possibly think of that would cause HR to drop when under exertion is coronary heart disease, or CAD.

That's one of the things they look for in stress test, if the HR does not respond properly or as-expected during the test they will order more tests to rule out CAD.  Responding properly means things like not increasing in rate, not being able to get to max predicted rate for age, and measured efficiency.

[CMKOfromAZ]

Yes,  I've found the hand grips on the treadmill useless. I always joke that it's only a random number generator.

I am using a Polar chest strap on a Polar ready treadmill and with a Polar wrist watch. On your good advice, I have considered that my chest strap is poorly adjusted and shifting when I run so the heart rate readings are inaccurate. I have purchased a new, coded, fabric chest strap in a smaller size so I can mess with the fit. Also, I hear that the coded transmitter will help avoid some interference. I have also switched to walking on a steep incline rather than running to get my heart rate up and still be able to check my pulse manually. My manual readings are highly erratic, but I honestly find it hard to be panting and concentrating on keeping up with the treadmill and counting heartbeats and watching the stopwatch all at the same time. I'm convinced my manual readings must be inaccurate because they are so erratic, so I am hoping the monitor will give me clearer answers. I will confirm again when I get my new gear.

Jerry_NJ: My resting heartrate is indeed high. I'm only 41 and my HR runs around 80 when truly resting (laying on the couch) and in the mid to high 80's when I'm up walking around. I saw a cardiologist a couple of years ago for shortness of breath and really feeling my heart pounding in my chest. He told me there was nothing wrong with me other than I was in terrible shape and needed to start working out. I've finally gotten around to taking his advice but I'm really struggling and huffing and puffing... Which is why I thought I better make sure I'm really working in a good HR range.

Thanks All for your advice. I'll let you know how the new equipment works for me.

[Jerry_NJ]

I think the last post raises a number of good points.  I too do not believe you HR is going down.  Can you measure physically e.g., with your finger on your wrist or neck or were ever you can "feel" you pulse.  When exercising it should be easy to feel you pulse physically - give it a try, you also need a watch/clock with a second "hand".

You didn't mention you age, but a resting HR of 88 is a bit on the high side.  Have you ever discussed the high HR with a doctor?  If you are under 50, I'd think a resting HR well below 80 would be a much better "sign".  

I have found when running (anything over 5 mph for me) on a treadmill it is hard (and not recommended) to hold onto the hand grip heart monitors.  I too use a chest strap, and it sends a signal most exercise machines can detect, so I get a reading on the machine and don't have to look at my wrist watch display.  Whenever I have gotten strange readings, usually high as I recall, I found a problem with  the chest strap/battery something mechanical/electrical not my heart causing the reading anomaly.