Suunto Smart Heart Rate Belt 2

[Jan Van de Velde]

@Egika I do agree that wrapping a bicycle tube around the sensor seems to be ludicrous. However one can’t say that it is working properly. Herewith some examples from the last 3 weerks:

• The firsts run was immediately the worst. I tightened the belt afterwards, this helped.
  
• The most recent run. Here it took about a half hour to pick up on my actual hearth rate. First a too low reading then to high and then too low again. The belt was sufficiently tight and moist.
  
• Another run. Here it took ‘only’ 10 minutes.
  
• Another run. Here it took 19 minutes (of a 33 min run) for a good reading.
  
  I also have issues with bike rides. Sometimes the HR just peaks to 180+ without any external reason but this is more difficult to show on the graphs. I switched from a H10 for the memory function of the SHRM2, but never had these issues before. Needless to say that I am seriously considering to return the unit. The only thing that is stopping me is the fact that Suunto has a history to make their hardware better with firmware updates.

[2b2bff]

Coming back to the running metrics. Especially for GCT:FT is there somebody that has values in the ranges of the description? I just wonder whether the data / description is wrong, or I might be really bad at this. Even during the last race I did the mean is 282.7%, well in the “inefficient” range…

[Speed Man]

@2b2bff
The foot stays in contact with the ground approximately 2.8 times longer than it stays in the air. This is why the app displays a value of 282.7%.

I suspect this figure may need to be divided by two because GCT is measured separately for the left and right feet. If we divide 2.8 by 2, the result is approximately 1.4.

However, this is only my hypothesis at this stage. We need to wait for Suunto to confirm how the GCT:FT Ratio is calculated before drawing any conclusions.

[2b2bff]

@Speed-Man in my books there are three possibilities:

• Calculation is wrong
• Explanation text is wrong
• My form is worse than I think it is

All of this could be the case at the same time. I just want to know

[VoiGAS]

Today, (different) merino shirt and electrode gel - its a mess

[Speed Man]

@VoiGAS I’m not sure if it’s caused by the way you’re wearing it or its position, but it seems to vibrate.

For me, it works well, even when wearing a 100% polyester shirt, as long as it’s a lightweight sleeveless top. I do occasionally experience some dropouts, possibly when increasing speed or due to vibrations during movement.

[VoiGAS]

@Speed-Man Interesting, thank you! It was a Trail Run and indeed this time I felt it was moving a lot.
Strange, because it was quite snug. I wear it on the lower half of the rib cage - is there a ‘perfect position’ for it?

[Egika]

@VoiGAS https://lmgtfy.com/?q=position+HR+chest+belt&t=i

[MarTej_cz]

@VoiGAS https://www.suunto.com/en-cz/Support/Product-support/suunto_ambit2_r/suunto_ambit2_r/pouivani-sportovnich-reim/nasazeni-hrudniho-pasu/

[VoiGAS]

@MarTej_cz @egika : Thank you, I think I deserve it…
I was hoping for personal experience with the Suunto belt. I heard there were even experiments like wearing it on the back or on the belly.

[MarTej_cz]

@VoiGAS Good . The belly-wearing experiment could be interesting, Watch

[Egika]

@VoiGAS without personal experience with back or belly, I would think that the electrodes do have a harder time picking up any ECG signal further away from the heart.
The belts are designed to be worn snug and with good skin contact in the position shown.

Btw: I am having no issues at all with new strap and belt

[2b2bff]

@Egika after doing recommended hard reset and a bit more wetting the strap than I had to with the older generation, it works quite well for me, too…

[Ze Stuart]

I had a half marathon on the weekend, and after reading this thread I thought why not? Let’s run it with two chest straps and two watches. If anyone has need of an overly detailed comparison of the two HR streams (Garmin HRM 600, Suunto HRB2), it’s here: https://zulusierra.co/garmin-hrm-600-and-suunto-smart-heart-rate-belt-2-comparing-heart-rate-and-raw-r-r-data/

I’m waiting for more data from Garmin and then I’ll publish something similar for the running dynamics piece.

[snow*]

@Ze-Stuart thanks for the detailed comparison, very useful.

A follow-up request, if you have time: could you publish a time series of the R-R intervals (or at least of the successive changes > 100 ms) for both straps? It would show whether the 613 large jumps in the Suunto file cluster in the first minutes or are spread across the whole run

[Ze Stuart]

@snow here you go: https://zulusierra.co/r-r-interval-follow-up-when-do-the-large-jumps-occur/

This stuff used to take me ages to crunch through. I was curious if terrain - the route had a few wicked climbs and drops - and corresponding changes in body posture would contribute to errors but it doesn’t seem so.

I also think the .8 firmware has been rolled back, as it no longer seems to be available.