Does fitbit really work?
Replies
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Best to use fitbit as a tool to gauge TDEE vs. kcals burned (i.e. 30 min treadmill) because fitbit captures BMR + activity as the day progresses (very useful for determining NEAT). Pretty hard to calculate & record things like time spent pacing, standing up vs. sitting vs. laying down on a day to day basis without fitbit or similar device.
Still need to calculate kcals consumed though vs. fitbit TDEE & assess progress (weight, tape measurements, etc.) to determine accuracy2 -
Mine seems quite accurate, (Charge 2 HR) it may understate slightly (I do quite a bit of higher impact stuff). My HRM (myzone belt) gives me a higher burn figure, but anything finds it harder to estimate at higher end of HR, so I hope by the lower.
I also like it because when I started on this journey it gave me a base line and a measure I could use to improve movement. It was motivating, and still is0 -
i did a little test today walked on treadmill for 30 mins... Treadmill said 150 cals, Fitbit was in the high 200's almost double.... Interesting lol.. Wonder which is right. (i entered in treadmill under exercise in fitbit while i did it)
FitBit is rarely going to “match” any number for exercise since FitBit is a total activity tracker and is measuring your BMR and NEAT in addition to the exercise burn.
Additionally when you look at the exercise adjustments in MFP from FitBit, a lot of people are confused and skeptical if they don’t understand what those adjustments represent: The diferemce between what MFP thinks you’d burn in a Day based on the stats you entered and activity level you chose... and the burn that FitBit estimates based on your total activity. It won’t match directly to an exercise output and if you’ve chosen Sedentary, but typically get 8k or more steps - your adjustments will be higher because you really aren’t Sedentary.7 -
Yes. I entered my info in treadmill. I also weigh and measure food when ever possible. So I think my calories going in are fairly accurate most days. Just gonna be careful not to eat back all my calories fitbit says I am burning. Maybe half lol. Burning that many calories just seems to good to be true lol.
One difference is Fitbit Versa will be continuously monitoring your HR. Once your HR gets high enough they start to use that in determining calories burned. A portion of the exercise burn is also your BMR and the treadmill likely reported NET calories not gross.
So for example:
175 calories during my 25 min workout this morning.
Of that about 23.3 was my BMR (based on estimated 14 calories burned every 15 mins for BMR).
So my NET was 151.7 for the workout.2 -
Oo that makes alot of sense. I understand
Thanks 0 -
I have a fitbit charge 2 and it's my companion for fitness every day. I love it. However, I view the calories burned differently than some people.
I really don't care if calories burned is accurate or not. Everyone is different and I don't think it's possible to have perfect accuracy. What matters is using calories burned as a reference point. So, I know if I consume 1800 cals or less from food and burn 3000+ cals according to fitbit, that calorie deficit leads to being right on track for my goals. I've tested it, so I'm going based on results. I know exactly how much weight I'll loose and inches I'll loose based on that reference point. I think its the best way to use calorie calculators like fitbit. Test it out, measure your results, and use it as a reference. Then it's highly accurate. Forget about the online calculators that take your age, height, etc...4 -
tbright1965 wrote: »
No, that was just the estimate for the ride. This is why I don't trust the estimates.
I tracked the entire ride on my Fitbit, pausing it during my brunch stop 35 miles into the ride. Fitbit estimated 4806 calories over 52.6 miles.
MapMyRide, also using GPS like my Fitbit Surge, I broke the ride into two rides. One, on the way to the brunch and a return ride.
Ride up, MMR claimed 3113 calories over the 34.9 miles up. It then claimed 1719 calories over the 18.4 on the way back. So again in the 4800 calorie range. Distance was closer to what the odometer on my bike indicated at 53.3. My bike odometer had 53.4 miles indicated.
After having slept, not sure where I got the 5200 calorie number from, so maybe I saw another number, or was just confused after (apparently) being in such a large calorie deficit (sarcasm.)
I don't allow myself to eat more than 1/2 of any recorded exercise calories.
I'm sure I burned a ton of calories. But I didn't burn nearly 5000 in 3.6 hours on my bicycle.
So I'd take calorie estimates with a healthy grain of salt.
My actual consumption yesterday was on the order of 2200 calories. I'm 5'11" and 215 pounds, FWIW.
Seriously, 2 woos?
So those who are giving woos, do you really trust that I'm burning over 1000 calories/hour, BMR + exercise?
I don't.
I'd LOVE for it to be true so I could plow through a box of thin mints. (Well, there is still T2D to worry about.) But it's not true, so I don't trust the numbers.
Woo away, sheesh!
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tbright1965 wrote: »tbright1965 wrote: »
No, that was just the estimate for the ride. This is why I don't trust the estimates.
I tracked the entire ride on my Fitbit, pausing it during my brunch stop 35 miles into the ride. Fitbit estimated 4806 calories over 52.6 miles.
MapMyRide, also using GPS like my Fitbit Surge, I broke the ride into two rides. One, on the way to the brunch and a return ride.
Ride up, MMR claimed 3113 calories over the 34.9 miles up. It then claimed 1719 calories over the 18.4 on the way back. So again in the 4800 calorie range. Distance was closer to what the odometer on my bike indicated at 53.3. My bike odometer had 53.4 miles indicated.
After having slept, not sure where I got the 5200 calorie number from, so maybe I saw another number, or was just confused after (apparently) being in such a large calorie deficit (sarcasm.)
I don't allow myself to eat more than 1/2 of any recorded exercise calories.
I'm sure I burned a ton of calories. But I didn't burn nearly 5000 in 3.6 hours on my bicycle.
So I'd take calorie estimates with a healthy grain of salt.
My actual consumption yesterday was on the order of 2200 calories. I'm 5'11" and 215 pounds, FWIW.
Seriously, 2 woos?
So those who are giving woos, do you really trust that I'm burning over 1000 calories/hour, BMR + exercise?
I don't.
I'd LOVE for it to be true so I could plow through a box of thin mints. (Well, there is still T2D to worry about.) But it's not true, so I don't trust the numbers.
Woo away, sheesh!
Whether you can trust your numbers to "eat" them or not depends on the interaction of:
--the quality of your food intake log
--the quality of your caloric expenditure log
--the quality of your weight change measurement
--how close to "average" you happen to be
All but the last are somewhat under one's control. You start by semi-trusting your numbers and you adjust based on results.
Cycling is a very well researched activity. A 15mph bike ride is a MET 10 activity. The higher the speed the more the MET value increases. Inclines and wind also have an effect. Some apps try to adjust for inclines and your bike's weight. (f.e. 16-19mph without drafting is about 12 MET)
A direct power meter would give you a better approximation. Strava will probably give you the most accurate estimation possible, short of being wired directly.
This means that a 100kg person engaged in that activity for 1 hour will burn approximately 1000 Calories (10 x 100 x 1)
Alternatively an 80kg person engaged in a MET 10 activity for 0.5 hours would burn ~400 Cal (10 x 80 x 0.5).
Whether YOU can eat those calories depends on the factors I outlined initially. However, this does not negate the fact that an average person engaged in that activity would, on average, burn this amount of calories.1 -
Bobthedog3232 wrote: »It’s fantastic when they work they can’t be faulted but they aren’t durable have had two and both have died just randomly lasted no more then a year charge 2 that is
This is why I switched to a Garmin Vivofit (I have the Vivofit 2). My first Fitbit stopped holding a charge after about 14 months. Vivofits use watch batteries so you never have to charge it. I just changed the batteries a couple of weeks ago after 3 years on the old ones.
No matter what brand of tracker you use, the more you use it and the more accurate your food logging is, the closer to real numbers it will become. After about 3 months of meticulous logging, my calories burned were within 100 calories of those I calculated using real time data.2 -
Let's keep it confined to one number, which is what I was talking about, the expenditure.
(Edited to add, I do realize I also posted my food consumption of about 2200 calories Sunday, so perhaps that causes some confusion. Just wasn't hungry on Sunday. It was Monday where my body wanted to eat all the foods.)
My logging is pretty good, but not really relevant to the idea that the Fitbit gets an accurate calorie number.
All the Fitbit knows is the GPS data it picks up, the HR data it picks up and how much I weigh, my age and gender. So it came up with ~4800 calories in 3.6 hours of work averaging just under 15MPH.
It doesn't know anything about wind. I do believe it has terrain data from comparing the GPS data to geodata out there.
So if I rounded up my speed and my weight to be 100kg (I'm a few kg below) I'd only get to 10x100x3.6 or 3600 calories, or about 3/4rs of the value presented.
I believe my sedentary burn is around the 100 calories/hour, so even adding on another 350 for BMR, I'm still below 4k, but certainly closer.
I do agree, to get a better reading, a power meter is needed.
What I've found works for me is to only eat back 1/2 of what MMR and Fitbit suggest are my burns. That has kept me on a 1-2 pound per week weight loss.
I do weigh calorie dense foods on my food scale. So if I have a omelette, I weigh the cheese,but not the veggies I put in it.
So far, for the past 7.5 months, that approach has allowed me to drop 50#
I simply caution people to be a little skeptical of the calorie burns offered up by such tools.
It would be unwise for me to take the 4800 calorie figure as permission to eat 4800 calories of cookies just because I rode my bike.Whether you can trust your numbers to "eat" them or not depends on the interaction of:
--the quality of your food intake log
--the quality of your caloric expenditure log
--the quality of your weight change measurement
--how close to "average" you happen to be
All but the last are somewhat under one's control. You start by semi-trusting your numbers and you adjust based on results.
Cycling is a very well researched activity. A 15mph bike ride is a MET 10 activity. The higher the speed the more the MET value increases. Inclines and wind also have an effect. Some apps try to adjust for inclines and your bike's weight. (f.e. 16-19mph without drafting is about 12 MET)
A direct power meter would give you a better approximation. Strava will probably give you the most accurate estimation possible, short of being wired directly.
This means that a 100kg person engaged in that activity for 1 hour will burn approximately 1000 Calories (10 x 100 x 1)
Alternatively an 80kg person engaged in a MET 10 activity for 0.5 hours would burn ~400 Cal (10 x 80 x 0.5).
Whether YOU can eat those calories depends on the factors I outlined initially. However, this does not negate the fact that an average person engaged in that activity would, on average, burn this amount of calories.
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I started with a Flex and moved onto a Flex 2 - both essentially higher tech pedometers. In the beginning it was a solid motivator. It reminds me if I don't get in 250 steps in an hour, tracks my steps, and tracks sleep quality.
I switch over to a Polar H7 for my endurance workouts.
If you're into gamification I'm assuming this will have a solid positive impact. It sets up a benchmark of 10k steps/day and you can adjust accordingly. For me it pushes me to continually improve.1 -
tbright1965 wrote: »Let's keep it confined to one number, which is what I was talking about, the expenditure.
(Edited to add, I do realize I also posted my food consumption of about 2200 calories Sunday, so perhaps that causes some confusion. Just wasn't hungry on Sunday. It was Monday where my body wanted to eat all the foods.)
My logging is pretty good, but not really relevant to the idea that the Fitbit gets an accurate calorie number.
All the Fitbit knows is the GPS data it picks up, the HR data it picks up and how much I weigh, my age and gender. So it came up with ~4800 calories in 3.6 hours of work averaging just under 15MPH.
It doesn't know anything about wind. I do believe it has terrain data from comparing the GPS data to geodata out there.
So if I rounded up my speed and my weight to be 100kg (I'm a few kg below) I'd only get to 10x100x3.6 or 3600 calories, or about 3/4rs of the value presented.
I believe my sedentary burn is around the 100 calories/hour, so even adding on another 350 for BMR, I'm still below 4k, but certainly closer.
I do agree, to get a better reading, a power meter is needed.
What I've found works for me is to only eat back 1/2 of what MMR and Fitbit suggest are my burns. That has kept me on a 1-2 pound per week weight loss.
I do weigh calorie dense foods on my food scale. So if I have a omelette, I weigh the cheese,but not the veggies I put in it.
So far, for the past 7.5 months, that approach has allowed me to drop 50#
I simply caution people to be a little skeptical of the calorie burns offered up by such tools.
It would be unwise for me to take the 4800 calorie figure as permission to eat 4800 calories of cookies just because I rode my bike.Whether you can trust your numbers to "eat" them or not depends on the interaction of:
--the quality of your food intake log
--the quality of your caloric expenditure log
--the quality of your weight change measurement
--how close to "average" you happen to be
All but the last are somewhat under one's control. You start by semi-trusting your numbers and you adjust based on results.
Cycling is a very well researched activity. A 15mph bike ride is a MET 10 activity. The higher the speed the more the MET value increases. Inclines and wind also have an effect. Some apps try to adjust for inclines and your bike's weight. (f.e. 16-19mph without drafting is about 12 MET)
A direct power meter would give you a better approximation. Strava will probably give you the most accurate estimation possible, short of being wired directly.
This means that a 100kg person engaged in that activity for 1 hour will burn approximately 1000 Calories (10 x 100 x 1)
Alternatively an 80kg person engaged in a MET 10 activity for 0.5 hours would burn ~400 Cal (10 x 80 x 0.5).
Whether YOU can eat those calories depends on the factors I outlined initially. However, this does not negate the fact that an average person engaged in that activity would, on average, burn this amount of calories.
To complicate things further "how close to the average person you are" takes a hit when you're a habituated athlete. You may personally have a 20% lesser expenditure for the same results as compared to, for example, me just because you're used to the exercise.
Also extremely long activities that are not an everyday occurrence probably do not require a complete eat-back if the goal is weight loss. HOWEVER, daily activities require much more careful balancing to avoid side effects.
Again I am referring to considerable activity. I note that MFP's very active setting is reachable with ~3 hours of walking a day.
It is one thing to go for a 4 hour bike ride one day. It is another thing to go for two of them every day! There was a full time bicycle messenger who also exercised on top posting a few days ago....
All this does not negate basic activity estimates based on population averages which is all that fitbit does. The only "magic" is that instead of you having to tell it I engaged in a 15 mph ride for 15 minutes, it sits there and guesses that you engaged in a 10mph ride for 5 minutes, and a 15mph ride for 5 minutes and a 20mph ride for 5 minutes, and produces a slightly different, and hopefully more precise and less biased by your own perceptions, average.
You mentioned earlier that you don't want to consider the full picture, only the expenditure. You can't. You can't judge the correctness of the expenditure directly. Only indirectly through the end results you get. Which are also influenced by everything else.0 -
tbright1965 wrote: »Let's keep it confined to one number, which is what I was talking about, the expenditure.
(Edited to add, I do realize I also posted my food consumption of about 2200 calories Sunday, so perhaps that causes some confusion. Just wasn't hungry on Sunday. It was Monday where my body wanted to eat all the foods.)
My logging is pretty good, but not really relevant to the idea that the Fitbit gets an accurate calorie number.
All the Fitbit knows is the GPS data it picks up, the HR data it picks up and how much I weigh, my age and gender. So it came up with ~4800 calories in 3.6 hours of work averaging just under 15MPH.
It doesn't know anything about wind. I do believe it has terrain data from comparing the GPS data to geodata out there.
So if I rounded up my speed and my weight to be 100kg (I'm a few kg below) I'd only get to 10x100x3.6 or 3600 calories, or about 3/4rs of the value presented.
I believe my sedentary burn is around the 100 calories/hour, so even adding on another 350 for BMR, I'm still below 4k, but certainly closer.
I do agree, to get a better reading, a power meter is needed.
What I've found works for me is to only eat back 1/2 of what MMR and Fitbit suggest are my burns. That has kept me on a 1-2 pound per week weight loss.
I do weigh calorie dense foods on my food scale. So if I have a omelette, I weigh the cheese,but not the veggies I put in it.
So far, for the past 7.5 months, that approach has allowed me to drop 50#
I simply caution people to be a little skeptical of the calorie burns offered up by such tools.
It would be unwise for me to take the 4800 calorie figure as permission to eat 4800 calories of cookies just because I rode my bike.Whether you can trust your numbers to "eat" them or not depends on the interaction of:
--the quality of your food intake log
--the quality of your caloric expenditure log
--the quality of your weight change measurement
--how close to "average" you happen to be
All but the last are somewhat under one's control. You start by semi-trusting your numbers and you adjust based on results.
Cycling is a very well researched activity. A 15mph bike ride is a MET 10 activity. The higher the speed the more the MET value increases. Inclines and wind also have an effect. Some apps try to adjust for inclines and your bike's weight. (f.e. 16-19mph without drafting is about 12 MET)
A direct power meter would give you a better approximation. Strava will probably give you the most accurate estimation possible, short of being wired directly.
This means that a 100kg person engaged in that activity for 1 hour will burn approximately 1000 Calories (10 x 100 x 1)
Alternatively an 80kg person engaged in a MET 10 activity for 0.5 hours would burn ~400 Cal (10 x 80 x 0.5).
Whether YOU can eat those calories depends on the factors I outlined initially. However, this does not negate the fact that an average person engaged in that activity would, on average, burn this amount of calories.
To complicate things further "how close to the average person you are" takes a hit when you're a habituated athlete. You may personally have a 20% lesser expenditure for the same results as compared to, for example, me just because you're used to the exercise.
Also extremely long activities that are not an everyday occurrence probably do not require a complete eat-back if the goal is weight loss. HOWEVER, daily activities require much more careful balancing to avoid side effects.
Again I am referring to considerable activity. I note that MFP's very active setting is reachable with ~3 hours of walking a day.
It is one thing to go for a 4 hour bike ride one day. It is another thing to go for two of them every day! There was a full time bicycle messenger who also exercised on top posting a few days ago....
All this does not negate basic activity estimates based on population averages which is all that fitbit does. The only "magic" is that instead of you having to tell it I engaged in a 15 mph ride for 15 minutes, it sits there and guesses that you engaged in a 10mph ride for 5 minutes, and a 15mph ride for 5 minutes and a 20mph ride for 5 minutes, and produces a slightly different, and hopefully more precise and less biased by your own perceptions, average.
You mentioned earlier that you don't want to consider the full picture, only the expenditure. You can't. You can't judge the correctness of the expenditure directly. Only indirectly through the end results you get. Which are also influenced by everything else.
Actually, I can in terms of the subject.
The subject is Does Fitbit Really Work.
Since fitbit doesn't look at my fork or weigh my food, the only real things we can answer regarding the fitbit is does it accurately track my activity.
Therefore, in the context of the question presented, I can and rightfully SHOULD limit the discussion to those things the fitbit purports to measure.2 -
I used to do some bike in front of my TV. Then I got a fitbit... and I pretty much stopped. I was burning maybe 200 calories in 1 hour - absolutely pathetic. Either that or my fitbit was really completely wrong (it has HR), but I suppose that it kinda makes sense compared to walking because you really only move your legs... (talking stationary bike here).
I'm still not sure how people get those 400 calorie numbers - I was KILLING my legs for less of a burn than a 1hour walk.0
This discussion has been closed.
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