Author Topic: Garmin's 'body battery' function  (Read 1601 times)

Garmin's 'body battery' function
« on: 31 May, 2024, 10:09:18 am »
Does anyone use a Garmin device that monitors 'body battery'? What are your thoughts? Can you use it in any intelligent planning capacity?  Do you find a correlation between it and how you actually feel? Do you find a low score precedes illness for instance? Or is it simply an interesting monitoring tool/number for you?

Re: Garmin's 'body battery' function
« Reply #1 on: 31 May, 2024, 10:29:02 am »
My Garmin does but I don't pay any attention to it.  Likewise the HRV readings.

I could easily read too much into the information and become paranoid so it's better for me to ignore the data.

Re: Garmin's 'body battery' function
« Reply #2 on: 31 May, 2024, 10:45:18 am »
Likewise the HRV readings.

Yes. Garmin's definition of stress it's not your common or garden variety, it's true. One does have to extend it. It does include what we normally think of as stress but also more broadly what is referred to as 'allostatic load'. I'll leave interested parties to search that, if you're so inclined.

I'm wondering if Garmin has a similarly proprietary definition of  'body battery' (or energy levels) and the term is intended to embrace a broader concept than simply how full of beans you feel.

I find it an interesting number with broad correlation but have no practical use for it.

Auntie Helen

  • 6 Wheels in Germany
Re: Garmin's 'body battery' function
« Reply #3 on: 31 May, 2024, 09:04:31 pm »
My chap finds the body battery measurement very helpful. It often shows him before time if he is coming down with something. And if he is recovering.
My blog on cycling in Germany and eating German cake – http://www.auntiehelen.co.uk


ElyDave

  • Royal and Ancient Polar Bear Society member 263583
Re: Garmin's 'body battery' function
« Reply #4 on: 31 May, 2024, 09:32:36 pm »
I ignore it completely. Garmin regularly tells me I need a rest day, my normal response "fuck off garmin"

HRV as I understand it has some validity
“Procrastination is the thief of time, collar him.” –Charles Dickens

Graeme

  • @fatherhilarious.blog 🦋
    • Graeme's Blog
Re: Garmin's 'body battery' function
« Reply #5 on: 31 May, 2024, 10:55:39 pm »
I haven't found body battery, hrv, or stress useful, but RHR has been a dramatic and reliable indicator of how I'm feeling. It's fairly constant until I'm unwell and gives me that clue almost a day or two before I notice. It also responds to any need for recovery.

T42

  • Apprentice geezer
Re: Garmin's 'body battery' function
« Reply #6 on: 01 June, 2024, 08:24:22 am »
I wouldn't rely on anything that produced sentences such as "Your day has started rather easy".
I've dusted off all those old bottles and set them up straight

Adam

  • It'll soon be summer
    • Charity ride Durness to Dover 18-25th June 2011
Re: Garmin's 'body battery' function
« Reply #7 on: 01 June, 2024, 08:31:18 am »
No, the body battery concept doesn't seem to take into account that people who cycle a lot on a regular basis recover far quicker than those who don't.
“Life is like riding a bicycle. To keep your balance you must keep moving.” -Albert Einstein

FifeingEejit

  • Not Small
Re: Garmin's 'body battery' function
« Reply #8 on: 01 June, 2024, 12:04:35 pm »
having recently got a forerunner 55,im finding it to be fairly inaccurate on these measures.
sleep tracking? no that wasn't REM that was doom scrolling for an hour before getting up, and that's impacting the body battery. the HR readings are generally OK until I move so I believe the RHR number to some extent.

I also find the fitness/freshness graph found in every cycling tool to be of limited accuracy though.

Sent from my IV2201 using Tapatalk


Re: Garmin's 'body battery' function
« Reply #9 on: 01 June, 2024, 01:29:30 pm »
I gave up trusting any of the body measurement stuff on my garmin watch when it told me I was in deep sleep when I could tell it exactly what Charlotte Smith was saying at quarter to six.
The heart rate monitor was interesting in relative terms, but seemed to use a lot of battery, so I've switched it off.
I only use it to track a ride/run these days, and it conks out after about 90 mins anyway.
Its less than 3 years old. (so just outside warranty)

ElyDave

  • Royal and Ancient Polar Bear Society member 263583
Re: Garmin's 'body battery' function
« Reply #10 on: 01 June, 2024, 01:49:53 pm »
I haven't found body battery, hrv, or stress useful, but RHR has been a dramatic and reliable indicator of how I'm feeling. It's fairly constant until I'm unwell and gives me that clue almost a day or two before I notice. It also responds to any need for recovery.

Me too, RHR is very useful, I know someone who noticed going up, got himself checked out and caught bowel cancer at a very early stage
“Procrastination is the thief of time, collar him.” –Charles Dickens

Re: Garmin's 'body battery' function
« Reply #11 on: 02 June, 2024, 08:53:43 am »
No, the body battery concept doesn't seem to take into account that people who cycle a lot on a regular basis recover far quicker than those who don't.

It was 3 days cycle touring (does 3 days constitute a "tour" ?) that gave me cause to look at the numbers on the app and think 'um, no, I don't think so'. My body battery depleted at the end of day 1 and did not recover until my 2nd night's sleep at home. So I did consecutive days of 90km with single digit body battery - and felt just fine.

Maybe it's not measuring what I think it is and I simply misunderstand it (that's always a good possibility) It does leave me with no notion of how it's any practical use though.

ravenbait

  • Someone's imaginary friend
  • No, RB3, you can't have more tupperware.
    • Someone's imaginary friend
Re: Garmin's 'body battery' function
« Reply #12 on: 02 June, 2024, 07:22:04 pm »
Body battery is fairly useless, but I do use HRV a lot. It can normally predict an asthma flare pretty accurately.

Sam
https://ravenbait.com
"Created something? Hah! But that would be irresponsible! And unethical! I would never, ever make... more than one."

Re: Garmin's 'body battery' function
« Reply #13 on: 02 June, 2024, 09:15:43 pm »
I have looked back at historical HRV data and I believe it can indicate when I am about to feel a bit low.  It does however show lows when I feel fine so not an absolute indicator.

Re: Garmin's 'body battery' function
« Reply #14 on: 03 June, 2024, 08:07:32 am »
My watch (a vivosmart 4) apparantly doesn't do proper, or full, or something, HRV but does give me a 'stress' value. It's a better indicator of when I'm awake or asleep than the sleep monitor is! Basically, if I'm awake then I'm 'stressed'. As I mentioned above though, Garmin doesn't use the terrm in quite the everyday understanding of it. It has a broader, and perhaps medically based application. Again, I find it an interesting number with broad correlation (my stress rises when I'm doing a hard maths sum) but it's difficult to know what to with it (except cease hard maths sums maybe)

citoyen

  • Occasionally rides a bike
Re: Garmin's 'body battery' function
« Reply #15 on: 03 June, 2024, 09:52:01 am »
My wife looks at the body battery scores and treats them as if they are scientific fact. I'm more sceptical, given that they're based on metrics the device can't measure accurately.

HRV is objectively a good indicator of stress. But I don't know how accurate the built-in optical HR monitor in Garmin devices is (they're still not as accurate as chest straps afaik), and I don't know how Garmin calculate stress - presumably they factor in other metrics beside HRV.

These things are useful up to a point but they aren't to be taken too seriously.
"The future's all yours, you lousy bicycles."

Re: Garmin's 'body battery' function
« Reply #16 on: 03 June, 2024, 10:02:14 am »
The only purpose in the 'Body Battery' as I see it, is for a kind of reverse flex at work- it's 9:30 and my battery is at 34%.

I find HRV to be equally useless- yes, when I am ill the HRV is lower. But yes, I am looking at it because I am feeling ill. There's no forecasting effect visible.

I treat its recovery estimates with equal disdain. (24+ hours for riding to work, less than 10 for swimming 2 miles. I know which of those I can manage twice a day and it isn't the work one.)

Re: Garmin's 'body battery' function
« Reply #17 on: 11 June, 2024, 05:24:11 pm »
I find HRV a useful warning when I am overdoing it. It gets low, I back off, sleep more, it goes up, I feel better.

Wholly unscientific I know!
Does not play well with others

Re: Garmin's 'body battery' function
« Reply #18 on: 24 June, 2024, 08:24:38 pm »
For me RHR goes up 2 a day or two before I show symptoms of a bug = very useful.

HRV isn't accurate on any smartwatch or chest strap. AIUI medical HRMs use 12 channel sensors but these are 2 or 3 at most iirc. You might get lucky with an accurate record but it won't be an accurate measurement just luck.

Body battery is based on inaccurate measurements so useless.  If you go on the garmin reddit you'll see a kind of flex where someone gets a 0 or a full 100. Like someone who got 100 the night after a very hard workout day.

Re: Garmin's 'body battery' function
« Reply #19 on: 25 June, 2024, 09:21:34 pm »
For me RHR goes up 2 a day or two before I show symptoms of a bug = very useful.

HRV isn't accurate on any smartwatch or chest strap. AIUI medical HRMs use 12 channel sensors but these are 2 or 3 at most iirc. You might get lucky with an accurate record but it won't be an accurate measurement just luck.

Body battery is based on inaccurate measurements so useless.  If you go on the garmin reddit you'll see a kind of flex where someone gets a 0 or a full 100. Like someone who got 100 the night after a very hard workout day.
I may be misunderstanding but pulse in a clinic /ward will generally be taken through photoplethysmography (pulse oximeter) at your fingertip in exactly the same way as a watch.  In an operating theatre we would use a 3/4 lead ECG and pulse oximeter and both give the bpm.  Generally they are within a beat of each other.  A 12 lead ECG is only used for identification/diagnosis of problems

A chest strap using electrical signals will be pretty accurate as soon as you are sweaty enough for good skin conduction.

Re: Garmin's 'body battery' function
« Reply #20 on: 26 June, 2024, 08:41:58 am »
Yeah!  Maybe I'm mistaking HRV with the various rhythm issues afib for example. It was in a discussion about smart watches and detecting afib, HRV, etc.

Definitely no expert but it does seem that people and perhaps smartwatch marketing teams attribute too much capability to their products. Not least because whilst it's possible a watch sensor could be a good as say a hospital finger sensor the way it is used reduces the performance. There's no seal around the watch and movement too has an effect on performance I believe.

Whatever the truth is I understand that smartwatches really are for trending over time not outright accuracy.

ravenbait

  • Someone's imaginary friend
  • No, RB3, you can't have more tupperware.
    • Someone's imaginary friend
Re: Garmin's 'body battery' function
« Reply #21 on: 26 June, 2024, 10:35:53 am »
AIUI, HRV is basically how much your heart rate varies. So if underlying stress is driving your RHR up, because you're poorly or over-tired, that will narrow the window of your heart rate's min-max, and this is registered as increased stress (lower HRV). I guess if your min-max window is pushed wider because you're over-stressing yourself with intense exercise, this is what will give you a too high HRV.

I don't use any of these things as an absolute, but I do pay attention to trends, which is the correct approach according to my GP, who is happy to listen when I talk about how things are different from where they should be.

Sam
https://ravenbait.com
"Created something? Hah! But that would be irresponsible! And unethical! I would never, ever make... more than one."

Re: Garmin's 'body battery' function
« Reply #22 on: 26 June, 2024, 01:25:15 pm »
AIUI watches can't actually read the true HRV But uses algorithms to produce a "HRV" type of figure. Different brands even watches have different algorithms which give different results.

So what use are they? Perhaps as a rough trend it might have value.

BTW on my garmin I used the stress reduction breathing exercise function to see if it had any effect on the hrv / stress data. It did actually change it 27th an upwards trend! What's happening there? Meditating with breathing exercise increases stress according to garmin fenix 6. In suspect it only goes to show hrv and stress is to be considered with a huge pinch of salt!