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Maximal heart rate correct with Forerunner 235?

Former Member over 9 years ago

Hi all,

I own the 235 forerunner and have difficulties with trusting the maximum heart rate.

It is known that the signal is very jumpy and much less smooth as compared to using e. g. my wahoo ant+ belt. However, at full running speed the optical sensor showed 205 bpm while the belt showed only 199 (two independent recordings). I did not test it simultaneously because the 235 automatically locks on to the belt even after disabling the automatic detection. So i was unable to record the wahoo belt signal with my edge 1000 at the same time but independently from the optical values as recorded with the 235.

All I want to ask here is whether you would trust the max heart rate values of the 235 optical sensor despite the jumpy signal? Have you made similar experience with getting higher max values as compared to the chest belt?

Thanks Carl

0 chunkywizard over 9 years ago

I'd always trust the belt over optical, it's a much more mature technology.

CW

0 Former Member over 9 years ago

But is there a general tendency to over or underestimate the heart rate during high intensity runs? My impression was that the heart rate with the 235 appears higher than it really is.

0 chunkywizard over 9 years ago

If you have both a strap and optical then you will know the answer! Take the strap as correct and compare against the optical on the same activity.

CW

0 timgrose over 9 years ago

But is there a general tendency to over or underestimate the heart rate during high intensity runs? My impression was that the heart rate with the 235 appears higher than it really is.

I usually wear a strap as well. Max HR on the 235 for me sometimes is about right (usually on steady runs), sometimes too low and sometimes too high. The biggest variances tend to be in intervals when I change speed/effort rapidly.

If you examine a graph of HR, a "true max HR" is usually one where it does not suddenly jump to that high value.

0 Former Member over 9 years ago

Yes, a "true max HR" is usually one where it does not suddenly jump to that high value. It would be great to check the relative strength of such "outliers" of the optical sensor by direct comparison with the signal of the ANT+ belt but this seems to be not possible, as also described here:

https://forums.garmin.com/showthread.php?343746-How-to-avoid-chest-band-pairing-with-FR235