I have had good results with the current 2.6 sensor hub update of the 235. A few thoughts on my experience:
- There is not a lot of monitoring going on overnight. It takes a reading every couple of hours at most. But these readings seem pretty steady although not the lowest resting heart rate in a 24 hour period.
- My low resting heart rate takes place in the first hour or two after I wake. In previous versions, it took place an hour before waking until waking. (You can see the stretch to the left of the little alarm clock - my reading around 54 throughout sleep through waking. The resting heart rate low of 42 took place around 10 am.)
- Resting heart rate averages are amazingly steady from week to week.
- The HR reading jumps to 90-100 when I start walking, even if when I take a manual HR read my pulse is still in the 60-70 range. I assume this is a false reading based on my walking cadence which is around 100. (The peaks below are during a half hour treadmill walk at a low speed; you can see it drop down immediately to a low resting rate once the walking stops.)
- The HR readings during exercise are extremely accurate. I'm not seeing a lot of false reading or dropouts like I saw in the previous firmware.
Postscript:
I have had the same problem on occasion that some other users have had - no HR reading at the start of an activity. I do check to see if the HR reading has started before the activity is begun - if not, I exit out to the main screen and restart the process. I haven't had this issue of late - but according to the forum that Garmin maintains, it is a known issue and they are working on it.
Also: I am having some unusually low resting readings - 39 is common, when a manual read is more like 46. I think Garmin has tweaked the algorithm productively, but still needs to do a little more with resting heart rates, particularly after exercise.
Additional postscript 5/8:
The update has killed vo2max readings on Garmin Connect. This is a known issue on the Garmin 235 forum.
So many times firmware updates from Garmin is like a game of whack-a-mole; one problem gets solved, another pops up. The latest dual updates from Garmin for the Forerunner 235 (WHR 2.6 updates the code for the Elevate heart rate module, 4.2 is a firmware update for the watch os) are true to form.
Improvement: the optical HR monitor is doing a better job during exercise. It seems like the heart rate is being updated on more like a one second than a 10 second or more basis. It locks onto real heart rate faster, is less confused from noise from your cadence (so-called "cadence lock" - where the optical hr monitor locks onto your footstrike cadence instead of your heart rate - why you may be seeing hr readings of 170 or more on easy runs), and is steadier over the course of a run - less spikes, more responsive to changes in effort. The run today was great - just a little spike around minute 45, but it actually may have been real given the increase in pace around that time.
Unfortunately, the bad comes with the good. Prior to this update, my resting heart rate is usually in a narrow band - usually 48-53. I've seen a reading of 40 once, but anything lower than that, or higher than 55 is abnormal.
This morning on waking, it looked as if the module did little or no reading during the night. It returned a resting reading of 50 as I was lying in bed, which is on target. But after the run, it showed a 36 resting heart rate. Not on target.
There have been a number of similar observations on the Garmin 235 forum. Hopefully they can get this resting HR issue straightened out quickly without undoing the good work as far as responsiveness during activities.
Edit: resting HR of 48 on day 2, so perhaps the device is making adjustments based on day-over-day data.
I am running the latest version of Garmin Connect Mobile (3.5.0.1) on a Nexus 5X.
I've now had two Garmin devices with built in optical HR modules -- the Vivosmart HR and the Forerunner 235. It is a huge advantage not to have to wear a chest strap, but the Elevate HR module is not perfect. For God's sake, it's not a medical grade EEG -- its a device that can aid in pacing and effort. Properly worn, the Elevate HR module in these devices works pretty well. However, I have found both devices can give erroneous HR info under the following circumstances:
1) It's cold out, and the device is worn over your sleeve or exposed to the elements. In this case, it is likely you will see some high HR readings for the activity - anywhere from 30-40 beats per minute faster than you might see otherwise. Fix: give your device a minute or two to "warm up" -- start an activity and wait a short time before you hit "start" and begin timing. Also - keep your sleeve over the device when you are running, at least until the device (and your skin) warms up a bit.
2) There is too much slack in the tightness of the wristband during activity. The tracker/watch should stay in place on your arm. Not so tight that you are leaving tracks on your wrist from the band, but not so loose that it moves at all when you are running. A loose device can mean spikes at the start of the run - as high as 40 beats per minute faster than where you should be -- and spikes once the run is underway.
3) Conversely, during resting periods, let it out a notch. I find that if its too tight during resting periods, it might show a higher resting heart rate than what you are experiencing.
With a little trial and error, you will find what works best, and most accurately, for you. I also hope that Garmin continues to improve devices with Elevate HR modules so the recording of both active and resting HR gets more accurate over time.
Overall, I have pretty good results (as good if not better than a chest strap) during activities when I have the proper tension set on the band, as below:
I've noticed some crazy spikes in resting heart rate (RHR) on the Garmin 235 even when sitting perfectly still at my desk. Here's one example:
Sort of looks like an earthquake (to the right and below the second little workout guy).
This never happens during exercise - only at rest. I filed a formal complaint with Garmin - was asked if I had the latest updates (a 2.5 Elevate module update, and the 3.3 235 firmware - yes and yes).
Turns out they are on the case - working on addressing this with a new upgrade. This is what I heard:
I took a look at your account, and I see the spikes you are talking about. Currently we are aware of some issues with the heart rate on the Forerunner 235, and are working on getting these resolved. This issue will be resolved in a future software update. Although there is no specific time when this update will be out, we are working as fast as we can to get it out to resolve these issues.
So hold on to your hats, the cavalry is coming, eventually.
