CICO maths and fitbit

Jacq_qui

Hi there,
Putting a spreadsheet together to try and troubleshoot my lack of progress. Is the basic sum this:

fitbit 'all day burn' - (calories that I eat + exercise calories) = deficit

eg fitbit says I burned 2500 calories, but on that day I ate 1400 + 400 = therefore deficit is 2500-1800 = 700 deficit

Feels like I've missed something here / double counted. I have MFP linked to my fitbit and trying to see where I'm going wrong. (Basically I think Fitbit is overestimating exercise cals)

Thank you

heybales

Why only exercise calories?
What % of your awake day time and what % of your total calories does exercise take up?

In case you get a lot of daily steps outside of exercise - ever walked a known 1/2 to 1 mile at avg daily pace (1.8 mph probably) and confirmed the distance Fitbit reported?

Your original formula isn't correct unless you are saying "calories I ate" and "exercise calories" are actually both calories that you ate, not sure how you plan to obtain this specific info split up to combine it again.

If you are just looking at the MFP stats of calories eaten, the formula is merely Fitbit daily burn minus MFP total eaten = deficit

That is CICO

Exercise is already included in the Fitbit daily burn.

While you are logging daily things though, you may indeed want to include a figure or two that is not included in the math for CICO, merely there for other math.
Perhaps you do want to note specific workouts as shown in Fitbit, time, calories, steps, distance.

And then for the daily Fitbit stats besides daily burn, steps and distance.

Because it's really distance that is used in daily burn calculations, steps is merely way to get that figure.
With those extra figures you can subtract exercise steps/distance/calories from daily and know what your NEAT level burn appears to be.
This can give a clue what happens on busy week with no exercise as far as eating level.

NovusDies

How long have you had a lack of progress?

Have you exhausted all efforts to make sure your logging is accurate? That is always the first place to troubleshoot. Are you using a food scale? Are you personally verifying the accuracy of the calories you use in the MFP database against a label or USDA site? That includes green checked items and barcodes.

nanastaci2020

Are you losing slower than expected, or not at all? And over how much time? Such as what is your weight now, what was your weight 30 days ago and 30 days before that? Any change at all or just +/- under 1 pound in the past 2 months?

Fitbit all day calories minus calories logged = deficit. If you're wearing it all the time, unless you're doing activity your Fitbit can't track (some models don't track swimming perhaps?) then you don't need to log 'exercise'. All day long burned calories includes exercise.

Now, if you're logging accurately (regularly using a food scale, not often estimating food calories because you don't really know what it contains) and you're not losing: there is the possibility that your Fitbit is giving you too much credit. How much of a deficit are you aiming for?

In your example, if Fitbit says you burned 2500 and you ate 1800 then yes deficit is 700. But if you ate 1400, deficit is 1100. Over the course of 4-8 weeks, you should see a change on the scales at either of these rates. BUT if you're not using a food scale, not accounting for beverage calories, cooking oils, often eating food made by others (so therefore having to estimate its quantity and contents) then you could easily be eating more calories than you think.

And if you've been at this for a week or 2 or 3, you may just need to give it more time.

Jacq_qui

heybales wrote: »

Why only exercise calories?

Hey, thanks for taking the time to reply-

In answer to this; Because I thought that fitbit daily burn is a measure of all the calories burnt from just being awake - I'm trying to work out what my deficit has been over the past month - and yes, by exercise calories I mean the additional calories I have eaten that have been rewarded to me for exercise. So I was wondering for my spreadsheet if I did daily burn minus everything I've eaten, that would be the deficit. I'm trying to see if it's either of these figures that could ruin my deficit and whether fitbit data is the problem.

ever walked a known 1/2 to 1 mile at avg daily pace (1.8 mph probably) and confirmed the distance Fitbit reported?

No I could try this though, using googlemaps to estimate a distance on a straight road. Cheers hadn't thought of that.

Your original formula isn't correct unless you are saying "calories I ate" and "exercise calories" are actually both calories that you ate, not sure how you plan to obtain this specific info split up to combine it again.

Yep that's what I am saying and agree, I can't split up what I ate (nor would it be overly useful), but I can see from those numbers if I've been rewarded say 800 calories for exercise, eat 600 of them back, but the actual calorie expenditure turns out to be closer to 550, then I've immediately lost my deficit!

Because it's really distance that is used in daily burn calculations, steps is merely way to get that figure.
With those extra figures you can subtract exercise steps/distance/calories from daily and know what your NEAT level burn appears to be.
This can give a clue what happens on busy week with no exercise as far as eating level.

Ok...so if I do a HIIT sesh in my front room, don't really travel much distance, but fitbit says I've burned 130cals for my effort, that isn't what is being fed to back to MFP, it's still using distance travelled over the day to calculate my calorie budget. If that is the case then perhaps the fitbit it could be less likely that is the cause of the problem?

Jacq_qui

NovusDies wrote: »

How long have you had a lack of progress?

Have you exhausted all efforts to make sure your logging is accurate? That is always the first place to troubleshoot. Are you using a food scale? Are you personally verifying the accuracy of the calories you use in the MFP database against a label or USDA site? That includes green checked items and barcodes.

Lack of progress since mid-september.

100% with you on logging. I started looking in October more closely at logging to make sure it was always tight enough because I have previously found that when there is no movement on the scales that I have got a little sloppy. Plus I knew at 3 weeks ish it was too early to assume that there was any other issue at play.

I do not personally check with USDA (does it have UK supermarket foods listed?) but pick a green tick where I can and if not, check the packets with what I have at home where it comes with one, or do my own recipe. Always a food scale. Always measure in g/ml. I don't rely on barcodes. I always read labels since my kids have allergies and anyway I often want an idea of how much of a portion I should put on my plate. I weigh fruit and veg.

I have the same breakfast every day, copy it over. I weigh out the yoghurt, seeds, nuts and muesli into the bowl. I do put in things like 0.5 apple (having selected the apple and I know that the weight is always correct within +/- 5g) and 2 strawberries or 5 blueberries. Some days it is 3 strawberries and no apple, depending on what fruit is left in the fridge, but I did spend one morning weighing it all out and actually the actuals came less than the estimates. A few berries are not ruining the deficit, I concluded!

Jacq_qui

nanastaci2020 wrote: »

Are you losing slower than expected, or not at all? And over how much time? Such as what is your weight now, what was your weight 30 days ago and 30 days before that? Any change at all or just +/- under 1 pound in the past 2 months?

Thanks for replying you've all been kind enough to help out here!

So I've actually gained weight in the last few months:
1st Sept. 66.1kg
1st Oct 66.3
1st Nov 67.3! (it's dropped off a bit since)
In this time period, my lowest weight was 65.5kg, highest was 67.4kg. But my current 7 day rolling average is 67.03kg (possibly hormones affecting that at the moment)

Fitbit all day calories minus calories logged = deficit. If you're wearing it all the time, unless you're doing activity your Fitbit can't track (some models don't track swimming perhaps?) then you don't need to log 'exercise'. All day long burned calories includes exercise.

Yes wearing it all day every day, only remove to charge. Don't log exercise separately onto MFP although do record it on fitbit - could that be the problem?? . Haven't been swimming recently and the only activity it might struggle to recognise is I use a scooter on the school run, however those short bursts of cardio won't have a significant step count associated with it as my arms are fairly still like bike riding - and it's probably only 1.4km for each school run. I have tried recording it as a 'work out', and a 'bike ride' and have now just given up trying to log it in case it is the cause of inflated estimates and therefore I don't think this is the problem.

Now, if you're logging accurately (regularly using a food scale, not often estimating food calories because you don't really know what it contains) and you're not losing: there is the possibility that your Fitbit is giving you too much credit. How much of a deficit are you aiming for?

Yes see above for food logging info. In sept/Oct I was aiming for a deficit of 250cals, which I know is really easy to destroy. I've now switched to 500cals deficit for this month out of desperation tbh. It doesn't seem right if I'm burning over 2000cals to be aiming to net 1200. This is where I feel the problem is...if I eat back these exercise calories i can be eating closer to 1700 or 1800 (although netting 1200) and MFP says well done you've been great, when actually I'm just totally wasting my time here.

Fitbit tends to give me quite high cals for my walks, usually 5km ish +/- 1km. It gives me anything between 280-400 cals back depending on how far I've gone, terrain and how fast I've walked I guess. Average speed is 6km/h

For HIIT I get around 130 for about 20something minutes -180cals for 40mins.

In your example, if Fitbit says you burned 2500 and you ate 1800 then yes deficit is 700. But if you ate 1400, deficit is 1100. Over the course of 4-8 weeks, you should see a change on the scales at either of these rates. BUT if you're not using a food scale, not accounting for beverage calories, cooking oils, often eating food made by others (so therefore having to estimate its quantity and contents) then you could easily be eating more calories than you think.

Tricky one. I don't use a lot of cooking oil or very frequently. I drink water, coffee with oat milk, and log the oat milk for the day rather than measure it out for each cup. I've worked this out by measuring out how much milk I use for one cup and then multiply by the day. I am the one who mostly cooks, if my partner cooks he knows to weigh stuff during cooking and he writes it down. (I'm lucky!)

And if you've been at this for a week or 2 or 3, you may just need to give it more time.

Yes, this may also be true. I was losing weight fine up until September. Now it feels like I'm doing something wrong and I can't work out what it is. A few people on my mfp friend list think it could be associated with starting back strength training in the gym, but now the gyms have just shut again today so I will have to see. Whereas I look at my diary and think ok Ive eaten 1800 cals in total, but fitbit says I have burned 2500 so that should be a good size deficit. That's a lot of error on my part !

heybales

What you are seeing in MFP is an adjustment between Fitbit reported calorie burn and MFP expected calorie burn.

What caused the difference could be exercise, no exercise and increased daily, or combo.

It's MFP correcting it's estimate of your daily burn to match Fitbit, and then taking a deficit basically.

That's why I commented getting exercise calorie burn from Fitbit, because that adjustment is not exercise.

So what you ate extra was not award by exercise always, hence my knowing you could not split that out as you planned.

You won't be able to tell if the issue is with Fitbit's estimate of your daily activity burn, or your exercise burn.

There are some known places for problems - like HR-based calorie burn on any workouts with HR all over the place or anaerobic like lifting will be inflated. Steady-state aerobic is only valid application of HR-based formula used.
HR-based calorie burn on like walks that bump into that method instead of staying at distance based will be inflated, because the bottom of the aerobic range is inflated that way for calorie burn.
Like distance-based calorie burn for daily activity when the stride length is wrong and distance is inflated.

But if you don't get many steps, if your workouts aren't very long, if , if - then some things won't matter.

That's why it's good to look to at what % is exercise of your daily calories and time.
15 min 3 x weekly even 100% inflated exercise in a very busy active life otherwise - no big whoop - your nutrition labels are more inaccurate than that would amount to.

But 2 hrs x 6 days weekly of hard cardio and life is really sedentary otherwise - now it matters how accurate.

Regarding that HIIT session - that inflated calorie burn is part of your total burned calories sent to MFP.
Rest of those total calories is BMR per calculation, and distance-based from other steps for daily activity.

sijomial

The maths exercise that might be interesting would be to take your last four week's numbers assuming your food logging has been complete and consistent.....

Add up total calories eaten, subtract 7,700 cals for kilos of weight gained. Divide that total by 28.
That gives you your average daily TDEE corrected for your personal food logging accuracy/inaccuracy.

Then add up your Fitbit daily total for the same period and compare the two numbers.

(Our gyms closing in the UK apart from being a PITA is unfortunately a confounding factor that will again muddy the waters regarding your calorie balance. It would be interesting to look back into the workout details and see what Fitbit guessed for your strength training though.)

Jacq_qui

heybales wrote: »

What you are seeing in MFP is an adjustment between Fitbit reported calorie burn and MFP expected calorie burn.

What caused the difference could be exercise, no exercise and increased daily, or combo

It's MFP correcting it's estimate of your daily burn to match Fitbit, and then taking a deficit basically.

That's why I commented getting exercise calorie burn from Fitbit, because that adjustment is not exercise.

So what you ate extra was not award by exercise always, hence my knowing you could not split that out as you planned..
You won't be able to tell if the issue is with Fitbit's estimate of your daily activity burn, or your exercise burn.

Gottit, thank you. I hadn't quite understood that the first time.

There are some known places for problems - like HR-based calorie burn on any workouts with HR all over the place or anaerobic like lifting will be inflated. Steady-state aerobic is only valid application of HR-based formula used.
HR-based calorie burn on like walks that bump into that method instead of staying at distance based will be inflated, because the bottom of the aerobic range is inflated that way for calorie burn.
Like distance-based calorie burn for daily activity when the stride length is wrong and distance is inflated.

So you pretty much just described the activities I do, HIIT (variable HR), walking (steady-state but in low cardio zone) and lifting. I usually have 9-12k steps a day, work outs are all sub 1hr, but the walking can be 1hr

But if you don't get many steps, if your workouts aren't very long, if , if - then some things won't matter.

That's why it's good to look to at what % is exercise of your daily calories and time.
15 min 3 x weekly even 100% inflated exercise in a very busy active life otherwise - no big whoop - your nutrition labels are more inaccurate than that would amount to.

But 2 hrs x 6 days weekly of hard cardio and life is really sedentary otherwise - now it matters how accurate.

Regarding that HIIT session - that inflated calorie burn is part of your total burned calories sent to MFP.
Rest of those total calories is BMR per calculation, and distance-based from other steps for daily activity.

I think I'm going to try taking my fitbit off when I exercise - for a week. I can put it my pocket if I want to track steps on a walk. I have to be eating too much. It's not rocket science......feels like that would be more predictable!

nanastaci2020

You've established that you've gained slightly over the past 2 months. Not a huge #, but if you thought you were eating in a deficit, 2 months is time enough to assess that something needs to change. Based on your logging, and what Fitbit shows you burned: can you calculate your rate of error? For example, if I'm burning 2000 on average and eating 1500 on average daily, I'd expect to lose 1 pound per week. If I gained 2 pounds after 9 weeks, that is an error of 11 pounds x 3500 calories. Because I expected to be -9, I am +2 and that is a range of 11 pounds. Which would indicate I was 'off' by about 600 calories per day. That error could be that i was burning less than I thought, eating more than I thought, or a combination of the two.


I personally would not log any exercise in Fitbit unless it is non-step based and/or you have reason to believe you can get a more accurate calorie burn estimate from another source. If you do, make sure you log the TIME correctly in Fitbit. For example, if you do Sumo Wrestling from 1pm-2pm, but log it from 2:30pm-3:30pm, then the logged entry is replacing calories Fitbit calculated in the WRONG time period.


Regarding the take off when doing XYZ activities: if Fitbit detects NO movement, it will assume BMR calories burned for that time period. You can either log your exercise for that time, or just know that the total burn #s reported by Fitbit is going to be low for you every day that you are not wearing it while you are being active. It does not assume that you are dead/not burning calories if it detects no heart rate.

Fitbit is great for tracking/counting step based activity. But each device and user is a little different. I find it accurate for me in terms of calorie burn, based on results. But other users have different results. Could it be off enough to account for all of your missing deficit? I don't know. If so that would mean your logging has been perfect.

My personal opinion on how Fitbit estimates burn: it is NOT based on 'distance' tracked by Fitbit. That metric is kind of like logging water here at MFP. Stat/data point not tied to anything. It does attempt to estimate your burn based on how much you're moving over a period of time. So if I'm casually walking around the grocery store for 60 minutes vs running at 6.0 mph for 60 minutes vs sitting at my desk for 60 minutes with occasionally getting up to move around the office: each of those hours will have different average per minute burn rates. And while you can set your stride length (how much distance you cover in a step walking or running) the reality is that your stride is not the same for every step you take in a day. If you want your miles in Fitbit to be accurate, it never will be. Example: I have tested it a good bit and I take longer strides when walking faster. I take about 1900 steps per mile at 3.8 mph. But only about 1730 at 4.0 mph, and its a little over 2000 steps per mile at 3.5 mph. I do not constantly change my 'stride' in Fitbit. But it recognizes, between the # of steps I'm taking (per minute, perhaps?) and my heart rate when I'm working harder or not. And my average calories burned per minute are slightly higher at 3.8 than 3.5, and higher still at 4.1.

If you stuck with me thru all of that, I would say to look for areas where you can improve your logging accuracy. Even the best logger is going to have errors. We are human after all. I can even tattle on myself, and I'm pretty OCD about accuracy. When I cook, I use the recipe builder. The next time i Make the same food, I often edit the recipe - because little things vary. I made chili a few months ago, and when logging it as I ate from the batch I thought the protein & calorie counts were a little low. But did not give it much thought. The NEXT time I made chili, and edited my recipe: I saw that the time before, I failed to add the ground turkey as an ingredient. OOPS. That was 5-6 meals over a few weeks. (I batch & freeze.)

AND whatever changes you make now: stay consistent with them for 4-6 weeks so you can judge results. If you change things up too often, you can't really know what is working and what is not.

nanastaci2020

Ps-I do not plan my goals, personally, on 'net calories'. I look at my TDEE and I set my goals based on that.

My bio:

Female, 46, 5'5" and right now 133 pounds. (New low weight this morning of 132.9 - woohoo.) I've been on the on again, off again cycle and lost 50 pounds in 2014 after getting my first Fitbit for Christmas 2013. From it I learned: I am lazy! Without effort I'd get 2000 steps most days. At that time I was around 180-185 pounds. My body simply did not burn enough in a day, based on my movement, to handle the food level I was eating which was probably about 2500 per day. I figured out that at maintenance, I'd need to move more to eat a 'normal' amount or plan to eat 1300-1400 forever.

So in 2014 I lost ~50 pounds over the course of 9 1/2 months. Started moving more, walking most days. Tracked my calories, first at Fitbit and finding MFP soon after. Learned about using a food scale, making recipes, etc. For a while I used the postage scale at work - then got a 2nd food scale for the office. After reaching goal, signed up for a half marathon (to take place Feb, about 4 months later) because I needed something else to focus on. Maintained around 130 for a while. Then went thru a few years where I'd gain 5-10, take it back off. Then 2018-19, was very lax (on activity AND logging) and gained a bit more. Based on my body & jeans, I can get to about 148-150 before my jeans don't want to cooperate. I got there last fall, started tracking and moving more again. Made progress over a few months and fell off again spring 2020. I could blame Covid, but I just got lazy. So by June: back up to 150ish. And I recommitted to EVERYTHING mid June.

What did that mean for me? Focus on ME and my health, well being. I set a daily step goal of 5000, which for me meant a TDEE of about 1650-1700. Was eating 1300-1400. Gradually increased my step goal. I got up to 10k daily, which means getting up early to walk in the morning and using my lunch hour mostly for strength training. Which has always been a problem area for me. It helps that school traffic is lighter, and my office location shifted slightly which makes my commute easier - so I can leave later. Now my TDEE is 1900-2000. My calorie goal is 1400-1700 and I aim to get in 100g protein minimum. I actually have MFP set to maintain, so when it shows 'calories left' that is actually an estimate of my deficit.

I am also taking care of myself in other ways. Getting regular hair cuts. Getting needed dental work taken care of. Replacing worn out clothes. Common, everyday things that sometimes we put off because it feels 'wrong' to put one's own self first. Be selfish: take care of you. Even if you have a spouse, kids, other responsibilities: you'll be able to contribute more to them if you make yourself a priority from time to time.

Now I am still tracking my weight, but I'm not really 'worried' about it. Whether I weigh 128-130 vs 132.9 is not significant. There are factors about my body that I want to improve, and those are not related to the # on the scale. And require me to put in work to maintain, build muscle mass and whittle away at some excess fat here & there. But I think the muscle/strength needs to be the priority.

heybales

nanastaci2020 wrote: »

And while you can set your stride length (how much distance you cover in a step walking or running) the reality is that your stride is not the same for every step you take in a day. If you want your miles in Fitbit to be accurate, it never will be. Example: I have tested it a good bit and I take longer strides when walking faster. I take about 1900 steps per mile at 3.8 mph. But only about 1730 at 4.0 mph, and its a little over 2000 steps per mile at 3.5 mph. I do not constantly change my 'stride' in Fitbit. But it recognizes, between the # of steps I'm taking (per minute, perhaps?) and my heart rate when I'm working harder or not. And my average calories burned per minute are slightly higher at 3.8 than 3.5, and higher still at 4.1.

That's what is interesting about the chips used for accelerometers, they contain the formulas for all kinds of things built in, whatever is using them only has to feed them some values, and read back whatever is desired.

One of the functions is exactly for distance based on impacts. Some devices incorporate swing to help determine walk or run, some use hang time. Many of the device makers (like Fitbit) don't even tweak anything in the chip.
With a known mass and stride length - there is an expected impact reading.
If the reading varies, then the stride length is different for that step.
It dynamically adjusts distance for each step. (up or down hills throws this off)

But as can be imagined, it's better for accuracy to start in the middle of a range and adjust each way, not start at an extreme.

So if stride length was dead on correct for exercise level pace, it's ability to calculate the other extreme of grocery store shuffle will suffer from accuracy.

But set the stride length for the middle (usually about 1.8 mph for people), it'll have best chance of accuracy going up or down.

And that's why on a treadmill at a set speed and as you have observed different stride length in reality - it has ability to still get the distance pretty correct despite testing several speeds.

And if you've ever taken a walk below where it starts using HR-based calorie burn (that is it's own can of worms), most that I have looked up the distance-based calorie burn discover it's right on.

I've had people test different speeds to reach different HR's, and later look at their HR graph and you can see the moment it stops using distance-based calorie burn and calories jumps up to new level, for very minor increase in speed.

Deviette

So I'm running a very similar spreadsheet using my fitbit calories burnt and my MFP food logging!

One thing you do need to remember is that the amount of "calories burnt" by exercise on fitbit also includes the calories that you get for just being alive anyway. So for example: if you go for a run for an hour, afterwards your fitbit tells you you've burnt 500kcals for that run. But if you hadn't gone for a run you would've burnt around 75kcals just by sitting on the sofa watching TV (depending on your stats). You've only actually gained 425kcals extra from the run. These difference seem small, but the longer you're exercising, the more of an effect that it'll have, especially if it's low intensity exercise (such as walking).

Now this shouldn't affect the numbers on an in vs out sheet, it can make it seem like you're burning more calories from exercise than you actually are. I'm not sure how you're sorting out your in vs out. Personally I pull my out data straight from the fitbit app for my calories out, then use my total consumed value from my food diary on MFP.

I did notice you mentioned that you lift. HR monitors can be particularly poor at working out your burn for this. While lifting does burn calories, the HR to calorie burn isn't the same distribution as cardio, so if your heart rate is really high it might think you're doing some very intense cardio and assign you lots of calories that you're just not burning. I've heard that if you use the "weights" activity, it does help with this, but I don't have suitable data to verify this myself (I don't do weights). Alternatively you can just take it off when you're lifting weights then put it on afterwards.

Another thing to do is just to compare what you *should* be losing, to what you are losing. I find using trendweight useful for this because it has a little bit that says "you are burning x/day more than you're eating", then I compare that with my "theoretical" burn from my spreadsheet over the same time period (I suggest 4 weeks if you're somebody who has periods, that's what I do). The difference between the two is either logging errors, or fitbit over estimating your burn. The difference could be small, but combined over a long period of time, could make your loss very small or explain plateus. With this info it's easy to mentally adjust the daily goal on your MFP (or you could actually adjust your daily goal).

So for me for example. I'm finding that I'm losing slower than expected. The difference between my actual daily deficit and my theoretical is 50kcals. That's not a lot (although that is 350 a week), but it does suggest that there's probably something slightly up with either my logging, or my fitbit out numbers. Now I know I'm not perfect with my logging, and 50kcals could easily be eaten up by an extra cup of tea that I missed, or the nibbling I do when cooking. I found this most useful when I first started logging however. I had an exercise I wasn't able to wear my fitbit for (Judo) and so I had to estimate my calories out for it. Using this method made it much easier to adjust the amount of calories given to a much more reasonable number for my estimate (because the MFP database entry is just a little bit silly).

I wasn't expecting this post to become an essay ... Best of luck!

nanastaci2020

My Fitbit tracked 'exercise' is NOT right, for me, for distance, unless I'm walking 3.8 mph which is what my stride length is set to in Fitbit. If I walk faster (fewer steps) it gives me fewer miles and if I walk slower (more steps) it gives me more miles. But the calorie burn is reasonable - slightly higher burned per minute when faster. Not a great deal, something like 4.1 mph is .2 calories per minute more than 3.8 mph, and 3.8 mph is .2 calories per minute more than 3.5.

I have turned off my Fitbit's ability to set my stride length based on GPS. Because the last GPS tracked 'event' I did involved climbing hundreds of stairs. 600+ up, 600+ down, repeated twice. Lots of steps but very little 'distance' covered. Most of my walking these days is indoors on a treadmill so using that GPS reading for 'stride' would have made for wonky numbers for sure.

heybales wrote: »

nanastaci2020 wrote: »

And that's why on a treadmill at a set speed and as you have observed different stride length in reality - it has ability to still get the distance pretty correct despite testing several speeds.

And if you've ever taken a walk below where it starts using HR-based calorie burn (that is it's own can of worms), most that I have looked up the distance-based calorie burn discover it's right on.

I've had people test different speeds to reach different HR's, and later look at their HR graph and you can see the moment it stops using distance-based calorie burn and calories jumps up to new level, for very minor increase in speed.

nanastaci2020

@Deviette an error of 50 kcals per day could also just be the difference between your actual and what the scientific equations dictate an average person of your height/weight/age/gender SHOULD burn based on your activity.

heybales

nanastaci2020 wrote: »

My Fitbit tracked 'exercise' is NOT right, for me, for distance, unless I'm walking 3.8 mph which is what my stride length is set to in Fitbit. If I walk faster (fewer steps) it gives me fewer miles and if I walk slower (more steps) it gives me more miles. But the calorie burn is reasonable - slightly higher burned per minute when faster. Not a great deal, something like 4.1 mph is .2 calories per minute more than 3.8 mph, and 3.8 mph is .2 calories per minute more than 3.5.

I have turned off my Fitbit's ability to set my stride length based on GPS. Because the last GPS tracked 'event' I did involved climbing hundreds of stairs. 600+ up, 600+ down, repeated twice. Lots of steps but very little 'distance' covered. Most of my walking these days is indoors on a treadmill so using that GPS reading for 'stride' would have made for wonky numbers for sure.

heybales wrote: »

nanastaci2020 wrote: »

And that's why on a treadmill at a set speed and as you have observed different stride length in reality - it has ability to still get the distance pretty correct despite testing several speeds.

And if you've ever taken a walk below where it starts using HR-based calorie burn (that is it's own can of worms), most that I have looked up the distance-based calorie burn discover it's right on.

I've had people test different speeds to reach different HR's, and later look at their HR graph and you can see the moment it stops using distance-based calorie burn and calories jumps up to new level, for very minor increase in speed.

Ya this new method of trying to use GPS to constantly update is just waiting for issues to get big complaints about.
I'll have to see if Garmin has done similar - their fitness devices you enable it for a single test, then it uses it.