OHR and responsiveness

I recently lost my Scosche heart rate monitor and instead of replacing it I have been trying to use the monitor in the watch. It seems to work well enough when I'm sitting around but on a treadmill not so much. I have been trying to keep my heart rate at a particular rate for base building by varying my pace, but I'm finding that the reported rare jumps around quite a bit. If I put my hands on the treadmills heart rate sensors sometimes they match but they are often different by 15bpm. I know the treadmill can be off too. But the real issue is that the F5+ number will seem to sometimes jump around from say 128 to 135, or get stuck at a number like 135 when I can feel that it should be much lower.

Has anyone else seen this? Any tricks to make it work better? I wear it tightly on my wrist just above that bone that sticks out. My wrists are not big, which may be the problem.

0 Former Member over 6 years ago

One of the reasons I got a Fenix+ is that I can link a chest strap to it. The optical wrist-based stuff is fine for walking around, sleep monitoring and so on, but if cycling/rowing/running etc a chest strap is best and the Fenix lets you get the best of both worlds. Chest strap when exercising, optical wrist for fuss-free all-day data.

0 HeliosJim over 6 years ago

Thanks guys, I put the HRM4 Run on my Christmas list. I used a Polar chest strap years ago and never minded wearing it.

0 SAHO over 6 years ago

I think that’s a very good choice, and hopefully santa will treat you good this year.

And yes, HRM-Run gives HRV during running. Not sure if it goes into VO2max as you can get that from OHR as well, but it definitely goes into LT, and probably makes training effect, training load etc. more accurate as well. (If not directly, at least through a more accurate LT).

...and on top of that you will also get all the fancy running dynamics when using the HRM Run. :)

0 AllanOlesen67 over 6 years ago

. Not sure if it goes into VO2max as you can get that from OHR as well,

It does. Firstbeat use HRV to detect the intensity of your breathing, and they use this to figure out how close you are to your VO2Max.

I don't know if the Firstbeat algorithm switches into another mode without use of HRV when you use the OHR - or if Garmin actually detects HRV from the OHR without telling us.

HRV can be found optically, so the latter would not be impossible. There are several phone apps doing that.

0 SAHO over 6 years ago

That’s very possible. I think Garmin does a lot of things without telling us :p

I reckoned that it the HRV from the OHR was disabled during activity, hence no data in the stress widget when moving/in activity.

0 HeliosJim over 6 years ago

...and on top of that you will also get all the fancy running dynamics when using the HRM Run. :)

Thanks for all the great info on the HRV, LT, VO2 and so on, that's just the kind of stuff I wanted to know!

So let me throw a small wrinkle in. I'm not sure if Santa will bring me a HRM4 but one of his helpers gave me a Stryd. Of course the Stryd won't help with anything heart rate related but it does generate the fancy running dynamics data. So... So, if I were to have an HRM4 and a Stryd which would be the source of the fancy data, or can it be controlled?

If it can be controlled which should I prefer? The case for the HRM4 is that it's located more centrally and in theory can make better data. OTOH, the Stryd can tell me all about how stiff my legs are, for what that's worth :-)

Since I now have the Stryd should I consider a different HRM?

0 AllanOlesen67 over 6 years ago

As far as I can see, you don't lose any data by having both. You just get some of them double, and some of them in two different formats:

You will get double up on cadence.
You will get vertical oscillation in cm from the Stryd and vertical ratio in % from the HRM.
You will get ground contact time from the Stryd and ground contact time balance from the HRM.
You will get stride length from the HRM only (though the Stryd would probably measure it much more precisely if it tried).

Here is an example:
https://connect.garmin.com/modern/activity/3216699324#.XBl4_HRVZGA.link

0 SAHO over 6 years ago

Allan is absolutely correct - I'll just add a few points as clarification:

Data from HRM-Run and Stryd are independent and using both at the same time doesn't cause any conflicts between them. In terms of which data to record, you don't need to choose - you get both.
In Allan's example you can see the data from Stryd presented in the graphs marked with IQ, and the rest is coming from either the HRM-Run or the watch itself.

If you are happy with the running dynamics from Stryd, you might as well get a more simple chest strap just for HR. I don't believe the HRM-Run adds anything compared to the HRM Premium Soft Strap in terms of accuracy or data quality for HR. I'm 99% sure you would still get HRV for LT etc. as well, someone is probably able to confirm.

0 AllanOlesen67 over 6 years ago

I'm 99% sure you would still get HRV for LT etc. as well, someone is probably able to confirm.

I can confirm that.

The only reason that I have a HRM-RUN is that I had some problems with my HRM Soft Strap (I don't know if it was a Premium or some lower model), so I bought the HRM-RUN to see if it got better (which it didn't). Both of them can measure HRV, and the watch will detect LTHR with both of them.

The HRM-RUN will report battery status. The Soft Strap will not. But I have never got a low battery warning from the HRM-RUN before the battery died, and when looking into the measured voltage (which is in the .fit file), it seems rather constant before and after a battery replacement. So I am not sure that this feature works as intended.

0 HeliosJim over 6 years ago

Allan and Saho, thanks VERY much, that's great info! It took me a few minutes to figure out what is what on the graphs, even though you guys explained it very clearly. Allan also thanks for posting the link, it's very interesting to look at your data. May I ask what your MHR and CP are?

I guess I'll go with the soft strap, although I just noticed that right now the HRM TRI is about $US 88 (on Amazon) while the soft strap is about $US 56. The extra capabilities of the HRM RUN may not be worth the extra $32 but the TRI might be.