24/7 HR Sampling

I've started noticing GC showing erroneous HR spikes during 24/7 activity tracking. See attached picture.

For some reason it keeps showing a HR spike that's neither real nor seen on the 4 hour watch HR plot - only in GC. The spike is usually at the same HR (about 156 in this case). It's happened in previous days but at a different HR number and not as often.

Anyone else seen this?

To be fair to Garmin, did they say anywhere that they were using the 24/7 HRM to calculate TDEE? They do use the OHR sensor (or chest strap) and FB technology in a specific activity like "run" or "bike" for calories and say with clear accuracy disclaimers, that general activity tracking is by a step counter. Neither would help if you wanted to use it for something like swimming or power lifting etc

That said, IMO they do deserve the heat they get to achieve better functionality from the OHR and be "encouraged" to get some more useful apps using that.

But surely if you have 24*7 HR monitoring the obvious thing to do would be to use that to more accurately calculate calorie burn? I have seen comments that activities such as walking burn few calories, but if you are active for a large part of the day then your HR will rise from say mid fifties resting to around 100 BPM and you will be burning calories. For me (according to my Fitbit) that can make a difference of up to 1000 calories per day. Fitbit HR does use HR to calculate calories. If I am on a stationary bike and don't activate the activity time then steps are hardly recorded (as there is no forward motion) but the calories logged increase significantly as would be expected.

The Garmin can do this also. Log an activity under "other" and do an activity where there is no distance, but just an increase in HR and you will be awarded calories. For me the calories calculated in activity mode seem about right and I am more than happy with them, but outside of activity they seem far too low, especially as in certain scenarios the steps are not recorded.

So unless Garmin use the HR data to calculate calories then is increasing the frequency actually pointless with maybe the exception of calculation RHR?

I've started noticing GC showing erroneous HR spikes during 24/7 activity tracking. See attached picture.

For some reason it keeps showing a HR spike that's neither real nor seen on the 4 hour watch HR plot - only in GC. The spike is usually at the same HR (about 156 in this case). It's happened in previous days but at a different HR number and not as often.

Anyone else seen this?

Yes originally about 30% of days, now it has done it for the last few days. In my case the spike may be different between days but once it occurs on a day it will occur several times at the same value. I have had them at 72, 106, 124

Fitbit HR does use HR to calculate calories.

OK...I am not that familiar with Fitbit but have used various activity trackers and open to any technology improvement. If I put the question another way, where does Fitbit say they use HR to calculate calories for the times it is not in an activity like a run? I guess they may use RHR for better estimating your base fitness level so they can say things like "taking into account".

I did find the excerpt below from their product description, which like Garmin does not mention using the 24/7 HR that way:

Although Fitbit Charge HR is most accurate for step-based activities like walking and running, you can receive credit and estimated caloric burn for any activity you manually log, activities automatically recognized by SmartTrack, and activity recorded when you put your tracker into exercise mode. Similar to the trip mode on a car's odometer, exercise mode provides you greater visibility to your exercise stats in a specified time frame, as well as real-time stats on your wrist.

Now the 1000 extra burn calories Fitbit shows may work in combination with entered BMR and other activity level for some but in my case I would have to walk another 30,000 steps, or alternatively be gaining about 1 kg per week. I believe the general individual profile one enters the factor in the calories burned taken for average steps.

I admit I was initially disappointed by burning apparent less calories (although not that much) for a same activity when I got the FR235 but then realised it was better at measuring my improved fitness level which is better.

During the day I am seeing very short spikes of HR above 130bpm with no special activity.

Also, the RHR for the last 7 days shown on the watch screen completely differ from the chart on Garmin Connect.
RHR displayed on the watch differ sometimes by 20bpm from day to day. On Garmin Connect RHR typically changes
by 2 or 3bpm from one day to the next day, which makes much more sense to me ...

Here they said:
Our PurePulse heart rate tracking is the only heart rate technology to offer automatic, continuous wrist based tracking for all-day health insights and workout intensity. It is uniquely designed to measure heart rate all day, with always-on optical heart rate sensors that still maintain extended battery life. PurePulse allows you to accurately track workout intensity and calorie burn with finely tuned algorithms that provide insight through interactive charts and graphs."[/INDENT]

Nothing in there saying they calculate TDEE based on 24/7 HR. In fact they use the words calorie burn along with workout intensity implying an activity.

However, I do agree it is "continuous" and will "give health insights" and "workout intensity" and that some part of the daily calorie burn is derived from HR data (as does the FR). It appears to use algorithms when it senses above 50%MHR. I also note they had an update in November which tries to better sense what the activity may be when HR is elevated so they can try to adjust the algorithm specific to the activity! Below that I can also have a cup of coffee or watch an exciting sports match to simulate exercise.

Plenty of people on the Fitbit forums may not agree with accuracy claims though and I do not agree that the FR I have is understating my calorie burn by 1000 which originated this. That makes neither case right or wrong for the individual. I am curious why a number Fitbit fans are looking at the FR235, being primarily a runner's watch, for the main purpose of non-running rather than say a VSHR?

Link to Fitbit Surge page to calculation of calories: https://help.fitbit.com/articles/en_US/Help_article/How-does-Fitbit-know-how-many-calories-I-ve-burned/?l=en_US&c=Topics%3AFood_Calories&p=surge&fs=Search&pn=1

a link to the fitbit charge HR forum a few days ago...(typical cryptic answer but clearer re needing exercise mode): https://community.fitbit.com/t5/Charge-HR/Calories-Burned-And-Heart-Rate-Monitor/m-p/1078376#U1078376

Nothing in there saying they calculate TDEE based on 24/7 HR. In fact they use the words calorie burn along with workout intensity implying an activity.

However, I do agree it is "continuous" and will "give health insights" and "workout intensity" and that some part of the daily calorie burn is derived from HR data (as does the FR). It appears to use algorithms when it senses above 50%MHR. I also note they had an update in November which tries to better sense what the activity may be when HR is elevated so they can try to adjust the algorithm specific to the activity! Below that I can also have a cup of coffee or watch an exciting sports match to simulate exercise.

Plenty of people on the Fitbit forums may not agree with accuracy claims though and I do not agree that the FR I have is understating my calorie burn by 1000 which originated this. That makes neither case right or wrong for the individual. I am curious why a number Fitbit fans are looking at the FR235, being primarily a runner's watch, for the main purpose of non-running rather than say a VSHR?

Link to Fitbit Surge page to calculation of calories: https://help.fitbit.com/articles/en_US/Help_article/How-does-Fitbit-know-how-many-calories-I-ve-burned/?l=en_US&c=Topics%3AFood_Calories&p=surge&fs=Search&pn=1

a link to the fitbit charge HR forum a few days ago...(typical cryptic answer but clearer re needing exercise mode): https://community.fitbit.com/t5/Charge-HR/Calories-Burned-And-Heart-Rate-Monitor/m-p/1078376#U1078376

I'm a runner and tracking of this activity with Fitbit is awful. But daily activities including burned calories are nice for me. I already used FR220 in the past and like Garmin devices for running. The FR235 give me additional activity tracking and for this I decided to try it. I agree that the main purpose is running for FR235 and why not to improve it for overall daily measurement. Please don't misunderstand me I like really my new running watch ;)

For me I want

1.)24*7 tracking for calorie burn

2.) A means of accurately recording activities in terms of distance/hr/calorie burn.

Fitbit HR is excellent at 24*7 calorie tracking BUT is very poor in terms of a) interval training, running or otherwise. b) locking onto my HR for early morning cold activities such as indoor cycling. Optical HR monitors can be poor generally in both these cases so I am happy to wear a HR monitor when needed.

That left me looking at a watch or a band. I spend a lot of time at a computer at work and felt that a band, like the Microsoft 2 or the VSHR would get in the way. Looking at the Garmin 235 the specification matched what I wanted perfectly. Overall it has the potential to do just that. I just think there is something wrong with step count (too low when doing lots of small steps due to the fact that it doesn't count anything less than 10 steps apparently?) and elevated HR outside of activity mode doesn't seem to calculate sufficient calories with maybe GC just relying on steps to calculate this?

In the attachment you can see where the Fitbit starts adding the additional calories when the HR starts to spike due to being active (as opposed to recording an activity) with the calorie burn rising dramatically when getting into fat burn and cardio zones.

I don't claim to be an expert in these matters and maybe the Fitbit overestimates a bit, but I have used this for the past year and my weight loss generally equals my calorie deficit. I'm not sending my watch back as I hope it will improve and I like it for recording my activities, but for now I still wear my fitbit for 24*7 tracking and I would really like to just use my Garmin. I need to be convinced on the calorie tracking accuracy and at the moment I am not.

For me I want

1.)24*7 tracking for calorie burn

2.) A means of accurately recording activities in terms of distance/hr/calorie burn.

Fitbit HR is excellent at 24*7 calorie tracking BUT is very poor in terms of a) interval training, running or otherwise. b) locking onto my HR for early morning cold activities such as indoor cycling. Optical HR monitors can be poor generally in both these cases so I am happy to wear a HR monitor when needed.

That left me looking at a watch or a band. I spend a lot of time at a computer at work and felt that a band, like the Microsoft 2 or the VSHR would get in the way. Looking at the Garmin 235 the specification matched what I wanted perfectly. Overall it has the potential to do just that. I just think there is something wrong with step count (too low when doing lots of small steps due to the fact that it doesn't count anything less than 10 steps apparently?) and elevated HR outside of activity mode doesn't seem to calculate sufficient calories with maybe GC just relying on steps to calculate this?

In the attachment you can see where the Fitbit starts adding the additional calories when the HR starts to spike due to being active (as opposed to recording an activity) with the calorie burn rising dramatically when getting into fat burn and cardio zones.

I don't claim to be an expert in these matters and maybe the Fitbit overestimates a bit, but I have used this for the past year and my weight loss generally equals my calorie deficit. I'm not sending my watch back as I hope it will improve and I like it for recording my activities, but for now I still wear my fitbit for 24*7 tracking and I would really like to just use my Garmin. I need to be convinced on the calorie tracking accuracy and at the moment I am not.

Paul I complete agree with you in case of burned calories Fitbit is accurate. For running, walking, step counts and distance the the accuracy is terrible. For this I prefer to use FR235 and it have current a disadvantage in burned calories measurement with HR. I think this can be improved with different options in settings for sampling time of HR measurement over day.