FR235 HRM and Sleep Data Comparison

Thanks for the info, appreciate it.

Be interesting to know how it calculates calorie burn if the HRM doesn't register 24/7. One of the simple things that Fitbit has right is the constant HRM and therefore correlation to calorie burn. Whilst I appreciate you have to take some of the sleep/step/calorie info with a pinch of salt, it's good to have a reasonably accurate gauge of what I'm doing all day.

I agree... also, I am a data geek, the more the merrier :rolleyes:

I'm going to check it at the weekend as I think it will replace the Fitbit and Suunto in one device, plus with the smart phone functions as well.

I just hope it's going to be ok as I have a low tolerance for being a beta tester for manufacturers :-)

Then I would suggest to wait many more weekends before checking it out :) As you can see in this forum many issues are yet to be fixed!

I did some 500m walks today to do some checks on steps, stride length and estimated distance/pace.



Here is my more detailed thougths, specifically towards the stride lengths topic:

https://forums.garmin.com/showthread.php?336466-Stride-Length&p=768106#post768106

My most recent HR comparison.

It was a two hour tennis training. Maybe most of the users are mostly interested in running/cycling, however I want to use my device to track all my sport activities.

Blue: Polar H7
Red: FR235



As you can see, the FR235 is mostly off from what the H7 tells. Only during a few moments it was more spot on. I was wearing the FR235 as tight as I did when I did my runs... maybe for this it was not tight enough? Or maybe the optical HR is just not up to follow that kind of stop-and-go motion and HR changes...

Also, Polar gives me 1500 cals over those two hours while the Garmin only calculated 900 cals.

I think for tracking HR in an activity like tennis a chest strap is necessary for accurate results. For this I would have to get an ANT+ strap eventually. Then again, I might just go with the FR230 instead and enjoy better accuracy also for my runs.

My most recent HR comparison.

It was a two hour tennis training. Maybe most of the users are mostly interested in running/cycling, however I want to use my device to track all my sport activities.

Blue: Polar H7
Red: FR235



As you can see, the FR235 is mostly off from what the H7 tells. Only during a few moments it was more spot on. I was wearing the FR235 as tight as I did when I did my runs... maybe for this it was not tight enough? Or maybe the optical HR is just not up to follow that kind of stop-and-go motion and HR changes...

Also, Polar gives me 1500 cals over those two hours while the Garmin only calculated 900 cals.

I think for tracking HR in an activity like tennis a chest strap is necessary for accurate results. For this I would have to get an ANT+ strap eventually. Then again, I might just go with the FR230 instead and enjoy better accuracy also for my runs.

Having both a Suunto Ambit 2S for running, workouts etc, and a Fitbit Charge HR for general activity, there is a clear difference in what is registered. I've always put this down to the fact that one is right on the heart and the other some distance way. Because of this I've always accepted that there will differences as I can't see it's possible for one to be the same as the other.

I think if you consider this, you'll probably be prepared to accept they won't be the same, but guess it's how specific you want it to be.

I'm happy for some variation, because although I like the stats, I'm not hung up on it being 100% all the time. But, I also use it as a general guide to my fitness for runs, and my activity during non-run times i.e. sitting working, or walking the dogs.

By the way, I bought one today, but gave the retailer a good lecture on why I may bring it back... :D

Having both a Suunto Ambit 2S for running, workouts etc, and a Fitbit Charge HR for general activity, there is a clear difference in what is registered. I've always put this down to the fact that one is right on the heart and the other some distance way. Because of this I've always accepted that there will differences as I can't see it's possible for one to be the same as the other.

I think if you consider this, you'll probably be prepared to accept they won't be the same, but guess it's how specific you want it to be.

I'm happy for some variation, because although I like the stats, I'm not hung up on it being 100% all the time. But, I also use it as a general guide to my fitness for runs, and my activity during non-run times i.e. sitting working, or walking the dogs.

By the way, I bought one today, but gave the retailer a good lecture on why I may bring it back... :D

What did the retailer say? :)

I guess you choose the right approach for this. Currently I am considering two options:

a) stay with the 235, get an ANT+ HR chest strap for activities where I want more accurate readings (as intervall runs, tennis trainings, HRV readings) and use the optical sensor just for everyday monitoring and maybe some easy runs, or for situations where I just forgot to bring the strap

b) return the 235 (with awfully bad battery life) and get a 230 and a chest strap. Hence no everyday HR monitoring and needing the chest strap for all activities.

I currently tend towards option a) however I am very disappointed in battery life...

What did the retailer say? :)

I guess you choose the right approach for this. Currently I am considering two options:

a) stay with the 235, get an ANT+ HR chest strap for activities where I want more accurate readings (as intervall runs, tennis trainings, HRV readings) and use the optical sensor just for everyday monitoring and maybe some easy runs, or for situations where I just forgot to bring the strap

b) return the 235 (with awfully bad battery life) and get a 230 and a chest strap. Hence no everyday HR monitoring and needing the chest strap for all activities.

I currently tend towards option a) however I am very disappointed in battery life...

They just said bring it back if you have any issues :D

I've found battery life is ok at present. From when I set it up yesterday and charged it to 100%, to after I went on my run this morning it had only gone to 86% after approx 14 hours. Granted, some of that was sleeping, but I'll be monitoring over next few days, especially now I've set up bluetooth etc.

I read somewhere that Garmin are working on battery issues, so perhaps stick with it?

It was great to go for a run this morning with no chest strap. The heart rate was a little lower than the Suunto, but I can live with that for the convenience of having it 24/7 and no strap. The GPS was very good. :cool:

I might try to turn off 24/7 HRM to test battery life without that. I also read that Garmin is working on the battery life subject and that they would probably change the intervals at which HRM is being recorded. I think it was in DC Rainmakers review.

Anyhow, here's another comparison between the FR235 and the Polar H7.

This time it was just a 3k/30min brisk walk. There was some serious dropouts. Don't think there's any crossover issue here, as cadence was avg 116 steps per minute and that's also more or less the avg HR. First you would think this is "perfect" for the crossover, that the optical sensor gets hung up on the cadence instead on the HR. But as I was keeping a steady pace, even then the HR reading from cadence should not have dropped.

Blue: H7
Red: FR235

I might try to turn off 24/7 HRM to test battery life without that. I also read that Garmin is working on the battery life subject and that they would probably change the intervals at which HRM is being recorded. I think it was in DC Rainmakers review.

Anyhow, here's another comparison between the FR235 and the Polar H7.

This time it was just a 3k/30min brisk walk. There was some serious dropouts. Don't think there's any crossover issue here, as cadence was avg 116 steps per minute and that's also more or less the avg HR. First you would think this is "perfect" for the crossover, that the optical sensor gets hung up on the cadence instead on the HR. But as I was keeping a steady pace, even then the HR reading from cadence should not have dropped.

Blue: H7
Red: FR235

At present all is OK for me, which I'm a little surprised about. With 1 run, BT on, HRM constant, and various times where I was playing with it, it went from 100% to 71% in a 24 hour period. That seems ok. It's below what they advertise, but I'm ok with that level of reduction.

I hope they don't just reduce the HRM intervals because that is detrimental to the activity tracking, especially the calorie burn. If they have an option to turn it off, that may make sense.

Anyway, they should be concentrating on sorting the battery issues, rather than robbing Peter to pay Paul.

The one thing I have found with Garmin is that they seem to struggle to produce a batch of devices that all work equally well. They are consistently inconsistent :D

At present all is OK for me, which I'm a little surprised about. With 1 run, BT on, HRM constant, and various times where I was playing with it, it went from 100% to 71% in a 24 hour period. That seems ok. It's below what they advertise, but I'm ok with that level of reduction.

Ever since I last charged 36 hours have passed. In between I have done 1 walk and 1 run with GPS on. I am now down to 85%, maybe I gained about 5% during sync connections with my PC. But still a 20% loss in 1.5 days is suddenly better than what I experienced so far. How come? Maybe because I reduced the constant checking of HR and steps

The one thing I have found with Garmin is that they seem to struggle to produce a batch of devices that all work equally well. They are consistently inconsistent

Haha.. that at least IS one form of consitency!


Here's another run. 6k about 50mins with a quick ATM stop in between. Good I had my running shoes on in case a mugger would want my € so I could just pick it up and fly off :-)

Blue: Polar H7
Red: FR235




In the beginning, the optical sensor struggled a tad more:




Then it got better:




Strange however what happened during my ATM stop. Maybe because I have smart recording turned on it calculated a linear drop of HR?




I think for the next run I will try to use the 1-sec recording vs. the smart recording. However I thought smart recording was just for GPS, not sure though, when I look at the exported TCX it seems to have a data point every 3-5 seconds or so.