Bad HR Data = Huge VO2 Max Drop

Former Member over 7 years ago

Just back from an easy 8 mile run with my girlfriend and throughout the run the 5S was reporting high HR. If you run enough you can sort of guess roughly what your HR is and I also run with an Apple Watch at the moment, which was reporting 20-30 beats lower than the 5S. So, I finish the run with what I think is bad HR data and when I check my VO2 max score its dropped from 58 to 55. It's never dropped by this much before - it usually only goes up or down by 1 point at a time.

If I delete the activity in its entirety then I know that the watch (and Garmin Connect) will still record the performance metrics (Load, VO2 Max, Race Predictor etc.). Is there anyway to fix this?

0 carl.andersson over 7 years ago

I don't think there's a way to fix this but the metrics should improve the next time you run so it won't be the end of the world.
Out of interest - did you have the Apple watch and the F5 on the same arm while running?

0 Former Member over 7 years ago

True. It’s a bit annoying though!

Nope. Apple Watch on the left and Garmin on the right. Apart from looking a total idiot (as opposed to a partial one for wearing one on each wrist), they would interfere with each other.

The colder weather seems seems to be an issue for wrist based optical sensors. I’ll have to go back to wearing my Tickr X — which itself isn’t wholly reliable.

0 mcalista over 7 years ago

I agree with carl - good data on your next run should have your VO2Max back where it should be. But agree the blip in the data is annoying too.

The most common cause of OHR problems is poor watch placement and positioning. The watch should be positioned high on the wrist away from the wrist bone, and the band should be fairly firm. I find I have to have the band one notch tighter for running than I do for 24/7 monitoring. The Fenix 5 is heavier and therefore more prone to "bounce" on the wrist than the Apple watch IF THE STRAP IS LOOSE.

One of the body's responses to cold weather is to divert blood flow away from the surface of the skin. This can make OHR more difficult. Of course, cold weather can cause problems with HR chest straps too, as the lack of sweat means poor electrical contact between sensor and skin - generally resolves itself 5 mins into a run as sweat starts, but pre-moistening the sensor pads can help too.

0 Dr Phil over 7 years ago

pre-moistening the sensor pads can help too.

I wet my HR strap with warm water every time before use so no problem with signal right from the beginning.

0 jmurenzo over 7 years ago

I use the scotsche external infrared heart rate monitor. Never had issues with it and I seem to get better / more consistent readings with it on.

0 Former Member over 7 years ago

Just back from an easy 8 mile run with my girlfriend and throughout the run the 5S was reporting high HR. If you run enough you can sort of guess roughly what your HR is and I also run with an Apple Watch at the moment, which was reporting 20-30 beats lower than the 5S. So, I finish the run with what I think is bad HR data and when I check my VO2 max score its dropped from 58 to 55. It's never dropped by this much before - it usually only goes up or down by 1 point at a time.

If I delete the activity in its entirety then I know that the watch (and Garmin Connect) will still record the performance metrics (Load, VO2 Max, Race Predictor etc.). Is there anyway to fix this?

Not that I know of, this is a constant problem with mine as well. If my heart rate were as high as the watch normally says it is I wouldn't be able to continue.