Burning less calories?
bdonahue12188
Posts: 8 Member
Hi All,
So. I’ve been working out since Sept 1. I use a Fitbit to measure calorie burn as it’s got a heart rate monitor. When I trained for an hour I would burn about 700-800 calories. Now, though I am doing more and lifting heavier weights and I’m only burning about 500.
Same goes for something as simple as walking. Walking 30 mins in the past Id burn about 300. Now, barely 200. Am I just getting fitter? Aka it takes me longer to build up a sweat or getting the heart rate up? I know the calorie burn from Fitbit isn’t really that accurate but even so it’s getting lower and is a rough gauge. Thanks for help!
So. I’ve been working out since Sept 1. I use a Fitbit to measure calorie burn as it’s got a heart rate monitor. When I trained for an hour I would burn about 700-800 calories. Now, though I am doing more and lifting heavier weights and I’m only burning about 500.
Same goes for something as simple as walking. Walking 30 mins in the past Id burn about 300. Now, barely 200. Am I just getting fitter? Aka it takes me longer to build up a sweat or getting the heart rate up? I know the calorie burn from Fitbit isn’t really that accurate but even so it’s getting lower and is a rough gauge. Thanks for help!
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Replies
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bdonahue12188 wrote: »Hi All,
So. I’ve been working out since Sept 1. I use a Fitbit to measure calorie burn as it’s got a heart rate monitor. When I trained for an hour I would burn about 700-800 calories. Now, though I am doing more and lifting heavier weights and I’m only burning about 500.
Same goes for something as simple as walking. Walking 30 mins in the past Id burn about 300. Now, barely 200. Am I just getting fitter? Aka it takes me longer to build up a sweat or getting the heart rate up? I know the calorie burn from Fitbit isn’t really that accurate but even so it’s getting lower and is a rough gauge. Thanks for help!
To start with, your calorie estimates are way off anyway. Nobody is burning 300 calories in 30 minutes of walking...not even 200. A good estimate for net calories burned walking is (bodyweight in Lbs X Distance X .33)
700-800 calories in an hour is also pretty hard to do unless you are an elite level athlete...500 is more reasonable.
One of the problems with estimates coming from HRM is that the algorithms used assume an average fit persons HR...if you're unfit and your HR is elevated simply because you are unfit, you calorie burn is going to be inflated. As you become more fit, your resting HR improves and normal exercise won't elevate it to the extent it did when you're unfit, so your estimated calorie burn is going to come down. If you are anywhere outside of the average...either unfit or very fit, your calorie estimates are basically worthless. If you fall within average, they can be more reasonable, but still very much an estimate.7 -
How much did you weigh on September 1, and how much do you weigh now? It takes less energy to move a smaller body than it does a larger body, so if you weigh less, you will burn fewer calories doing the same exercise than you did when you weighed more.
Your Fitbit's calculations seem pretty high, depending on what you were doing and how much you weighed.
Walking calories are about 0.3*weight*miles walked, for example. In 30 minutes one can probably walk 1-2 miles depending on pace. However, without knowing your weight, it's hard to say whether those calorie burn calculations are accurate for you.1 -
I weighed 230. Now weigh 213. I’m 5’9.5 Fitbit knows how much I weigh and my height.0
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bdonahue12188 wrote: »I weighed 230. Now weigh 213. I’m 5’9.5 Fitbit knows how much I weigh and my height.
Your Fitbit calorie calculations are off. @cwolfman13 gave some good explanations for what might be happening.
For a 30 minute walk, you're probably burning around 100-140 calories depending on exactly how far you're walking in that time.4 -
But you can't measure energy (calories) by heartbeats.
And estimating calories by heartbeats during strength training has virtually no correlation.
Just think of your heart as a pump - when you were less fit your heart didn't pump well, now you are fitter your pump is working better and pumps more blood per beat to deliver the oxygen to your working muscles.
Just for comparison my resting HR used to be around 60, now it's roughly 48. Doesn't mean I'm burning 20% less energy.
When I'm cycling I can produce roughly 25% more power (a good indication of energy expenditure) for the same HR.
Going purely by your numbers they seem hugely inflated estimates at first and are now drifting in the right direction.
Net calorie estimate per mile walking you are burning roughly 64 cals at 213lbs.
So yes as you lose weight if you do exactly the same weight bearing exercise you will burn less calories.
But normally as people get fitter they walk further, let heavier, exercise longer, intensity goes up.....8 -
Don't get myopic on calories burned that your fitbit gives you. It's not going to be accurate, but as everyone stated, you will burn less at a lower body weight, that's just the way the body works. Do note that you are burning calories, but exactly how much you won't know for sure. Instead, focus on what you can control, such as calories ingested and your performance. If you're lifting heavier weights and walking longer, those are positively objective numbers you can focus on that you can measure.2
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I don't agree with some of the posters saying its impossible to burn 700-800 cals in an hour. I am considered obese for my height and weight but i am stocky. At my recommended weight at 8% body fat, i looked anorexic. I am going off topic......Anyway, i probably have better cardio then most people. Even after a few years not doing cardio, after 2 months of HIIT i can hold a constant 160-170hr for an hour. And i burn 800 cal easy.0
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nytrifisoul wrote: »I don't agree with some of the posters saying its impossible to burn 700-800 cals in an hour. I am considered obese for my height and weight but i am stocky. At my recommended weight at 8% body fat, i looked anorexic. I am going off topic......Anyway, i probably have better cardio then most people. Even after a few years not doing cardio, after 2 months of HIIT i can hold a constant 160-170hr for an hour. And i burn 800 cal easy.
Who said "impossible"?
How are you measuring your calories burns while doing what exercise?3 -
Who said "impossible"?
How are you measuring your calories burns while doing what exercise?
Polar H7 chest strap w/polar beat app. So far ive noticed Polar beat records the lowest calorie burn then every single online calculator ive tried. Bowflex TC100. I do intervals between 2.5 to 3.5 mph keeping my avg hr at 165 bpm.
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nytrifisoul wrote: »
Who said "impossible"?
How are you measuring your calories burns while doing what exercise?
Polar H7 chest strap w/polar beat app. So far ive noticed Polar beat records the lowest calorie burn then every single online calculator ive tried. Bowflex TC100. I do intervals between 2.5 to 3.5 mph keeping my avg hr at 165 bpm.
That's counting heart beats - NOT energy. Two very different things.
I've seen people producing the same power / same net calories with HR of 120, 150 and 180bpm.
And by the way even if you are lucky that your HR is close to the predicted average for your demographic for steady state cardio doing intervals makes it even more suspect, the recovery periods with an elevated HR for the power being produced skews the numbers upwards badly.
Comparing an unverified estimate against online calculators doesn't mean yours numbers are accurate. And probably your Polar is guestimating gross calories not net calories which is the number you really want.6 -
nytrifisoul wrote: »
Who said "impossible"?
How are you measuring your calories burns while doing what exercise?
Polar H7 chest strap w/polar beat app. So far ive noticed Polar beat records the lowest calorie burn then every single online calculator ive tried. Bowflex TC100. I do intervals between 2.5 to 3.5 mph keeping my avg hr at 165 bpm.
The fact that it's the lowest number doesn't mean it's correct, it means it's lowest.
Heart rate monitors don't have any special insight into how much energy you're using. They provide a clue in the right circumstances, but it's just a guess.
See if you can get access to a bike with a power meter because this will be accurate for calories to +/- 2.5%. Unfortunately it tends to be an eye opening experience.5 -
nytrifisoul wrote: »
Who said "impossible"?
How are you measuring your calories burns while doing what exercise?
Polar H7 chest strap w/polar beat app. So far ive noticed Polar beat records the lowest calorie burn then every single online calculator ive tried. Bowflex TC100. I do intervals between 2.5 to 3.5 mph keeping my avg hr at 165 bpm.
The fact that it's the lowest number doesn't mean it's correct, it means it's lowest.
Heart rate monitors don't have any special insight into how much energy you're using. They provide a clue in the right circumstances, but it's just a guess.
See if you can get access to a bike with a power meter because this will be accurate for calories to +/- 2.5%. Unfortunately it tends to be an eye opening experience.0 -
Heart rate is a cool metric to have for fitness and general health measure, but as others have pointed out, it's a bit less helpful when it comes to determining calorie burn.
Over the last two months my resting heart rate has dropped from 100 bpm back down to 75 bpm. It's a sign that my anemia is clearing up and my blood is carrying oxygen more efficiently, so I'm glad I can track it. As far as I can tell it's not a sign that I'm burning less calories at rest. My actual step count/mileage is a better measure of my calories burned than my heart rate.
It's an interesting example I hope you don't experience, but it was an easy one to spot and cite, because the change happened relatively quickly.5 -
I’m 5’3” and 118-120 pounds. I know for a fact that 30 minutes of moderate treadmill walking, at my height/weight/age, burns around 90 calories. So unless you’re running at a full-out “gallop” for that same amount of time, I can’t believe it would be a lot more than 200 calories. 🚶🏻♀️🚶🏻♀️🚶🏻♀️3
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When I weighed 200lb+ and was very unfit (felt like I was dying when my hr hit 130), i could burn 700 Calories in 45min of zumba.
Now I'm only 140lb and (according to some) super fit, I'm lucky if i burn 400 in the same class despite jumping a lot more.
It's simply a consequence of being lighter and fitter, sometimes it bums me out. Especially as my PT is running a challenge right now to see who can burn the most calories in 45min (I dont stand a chance)1 -
Was the Fitbit new when you started? It also takes time for your Fotbit/garmin fill in brand of choice to get used to you.I am on my 5th HR wristband and usually the first three to four weeks of data kinda suck at the low and high end. In one case I even retired one as it never started working properly for me Just did not fit my wrist the right way.
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When I weighed 200lb+ and was very unfit (felt like I was dying when my hr hit 130), i could burn 700 Calories in 45min of zumba.
Now I'm only 140lb and (according to some) super fit, I'm lucky if i burn 400 in the same class despite jumping a lot more.
It's simply a consequence of being lighter and fitter, sometimes it bums me out. Especially as my PT is running a challenge right now to see who can burn the most calories in 45min (I dont stand a chance)
It's not a consequence of being fit.
But lighter, yes.5 -
NorthCascades wrote: »
The fact that it's the lowest number doesn't mean it's correct, it means it's lowest.
Heart rate monitors don't have any special insight into how much energy you're using. They provide a clue in the right circumstances, but it's just a guess.
See if you can get access to a bike with a power meter because this will be accurate for calories to +/- 2.5%. Unfortunately it tends to be an eye opening experience.
Well it may not be exact, but its close enough that i am eating back at least 75% of extra burned calories and i am still losing close to my weekly goal. I am not big on the science behind it, i just know that it works for me as i have lost a lot of weight the few times that ive gained it back, but that is my fault for not sticking to a healthy lifestyle for more then 3 years at a time.
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bdonahue12188 wrote: »I weighed 230. Now weigh 213. I’m 5’9.5 Fitbit knows how much I weigh and my height.
You are burning about 70 cals/mile walked. So 30 min is about 105.
Most fitness equipment and MFP have very overly generous algorithms for cals burned or they use gross instead of net.
Here are some accurate algorithms:
Running .63 x weight (lbs) = per mile cal expenditure (hills will increase this)
Walking .33 x weight (lbs) = per mile (hills increase)
Biking 3.6 x Ave watt output = 1 hour cycling at that rate
Looking for good swimming estimates. Haven't found. Hard to measure due to differences in efficiency. I do a little bit of yoga (not a lot) and the app estimates my cals and I cut that in half. I assume about 300 cals per hour of active (as opposed to meditative) yoga.
Hope that helps. MFP cal estimates for exercise I have found generally very over generous.5 -
nytrifisoul wrote: »I don't agree with some of the posters saying its impossible to burn 700-800 cals in an hour. I am considered obese for my height and weight but i am stocky. At my recommended weight at 8% body fat, i looked anorexic. I am going off topic......Anyway, i probably have better cardio then most people. Even after a few years not doing cardio, after 2 months of HIIT i can hold a constant 160-170hr for an hour. And i burn 800 cal easy.
It's definitely possible. If you are 200 lbs and run for an hour and do 6 miles, just under 800 cals. (.66 x 200 x 6). That's doing 10 min miles - far from an elite athlete!
But if you are 120 lbs...to produce the same burn in an hour you'd have to run 6 min miles and go 10 miles. Which isn't elite, but it's pretty damn hard. So body weight plays a factor.0 -
nytrifisoul wrote: »NorthCascades wrote: »
The fact that it's the lowest number doesn't mean it's correct, it means it's lowest.
Heart rate monitors don't have any special insight into how much energy you're using. They provide a clue in the right circumstances, but it's just a guess.
See if you can get access to a bike with a power meter because this will be accurate for calories to +/- 2.5%. Unfortunately it tends to be an eye opening experience.
Well it may not be exact, but its close enough that i am eating back at least 75% of extra burned calories and i am still losing close to my weekly goal. I am not big on the science behind it, i just know that it works for me as i have lost a lot of weight the few times that ive gained it back, but that is my fault for not sticking to a healthy lifestyle for more then 3 years at a time.
Whether the number is precisely accurate or not, yes, it is possible to come up with a trial and error “framework” that allows one to use even a moderately accurate metric as a guide.
That being said, your bowflex numbers are likely elevated and this is something to keep in mind in case the numbers stop working for you.
The average intensity for the TC 100 at a usual walking speed (like you describe) is probably about 4-5 METs (according to a study at Adelphi Univ).
Calories per hour is calculated by multiplying body wt in kg x METs. To hit 700 cals in an hour on the TC100, you would have to weigh between 308-385 lbs. (and not hold on to the handrails)
Again , this is not meant to disparage your workouts in any way. It’s more important that you have a routine that works for you, than it is to have the “right” numbers.
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jhanleybrown wrote: »
It's definitely possible. If you are 200 lbs and run for an hour and do 6 miles, just under 800 cals. (.66 x 200 x 6). That's doing 10 min miles - far from an elite athlete!
But if you are 120 lbs...to produce the same burn in an hour you'd have to run 6 min miles and go 10 miles. Which isn't elite, but it's pretty damn hard. So body weight plays a factor.
Close. I was 190 a few weeks ago, down to 187. But still, I know my 70 min TC100 climb is burning at least 800 cals.
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nytrifisoul wrote: »NorthCascades wrote: »
The fact that it's the lowest number doesn't mean it's correct, it means it's lowest.
Heart rate monitors don't have any special insight into how much energy you're using. They provide a clue in the right circumstances, but it's just a guess.
See if you can get access to a bike with a power meter because this will be accurate for calories to +/- 2.5%. Unfortunately it tends to be an eye opening experience.
Well it may not be exact, but its close enough that i am eating back at least 75% of extra burned calories and i am still losing close to my weekly goal. I am not big on the science behind it, i just know that it works for me as i have lost a lot of weight the few times that ive gained it back, but that is my fault for not sticking to a healthy lifestyle for more then 3 years at a time.
Congratulations on your weight loss, that's awesome! I hope it's making life better for you.
From what you just described, there's a huge range of uncertainty in your numbers. You don't know that you're bugging 800 kCal in 70 minutes. I'm not saying this to pee in your Cheerios, I'm saying it because it's the truth and we don't want to mislead people here.4 -
NorthCascades wrote: »
Congratulations on your weight loss, that's awesome! I hope it's making life better for you.
From what you just described, there's a huge range of uncertainty in your numbers. You don't know that you're bugging 800 kCal in 70 minutes. I'm not saying this to pee in your Cheerios, I'm saying it because it's the truth and we don't want to mislead people here.
Ok, what is wrong with my numbers? How many calories burned based on my numbers are in your opinion more realistic.
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Your gym probably has a bike with a power meter. If not, a lot of shops rent them out. You can even rent one from the internet.
Ride it for an hour. The kJ/kCal number it measures will be within +/- 2.5% of god's honest truth.
Use that experience - what the effort you put in felt like and the amount of work it accomplished - as a guide to better judge the calorie estimates other sources are giving you.1 -
nytrifisoul wrote: »NorthCascades wrote: »
Congratulations on your weight loss, that's awesome! I hope it's making life better for you.
From what you just described, there's a huge range of uncertainty in your numbers. You don't know that you're bugging 800 kCal in 70 minutes. I'm not saying this to pee in your Cheerios, I'm saying it because it's the truth and we don't want to mislead people here.
Ok, what is wrong with my numbers? How many calories burned based on my numbers are in your opinion more realistic.
Look at my previous post. Your average calorie burn is probably about 1/2 of what you are estimating.
The fact that you are using inflated exercise numbers and yet still losing weight just points out the inherent inaccuracies of trying to estimate calorie intake, exercise calories, and “movement” calories.
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The labels on packaged foods can be off by up to 10% in either direction, I would expect that to average out over time but unless you're using a food scale you don't know.0
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NorthCascades wrote: »Your gym probably has a bike with a power meter. If not, a lot of shops rent them out. You can even rent one from the internet.
Ride it for an hour. The kJ/kCal number it measures will be within +/- 2.5% of god's honest truth.
Use that experience - what the effort you put in felt like and the amount of work it accomplished - as a guide to better judge the calorie estimates other sources are giving you.
I have a stationary exercise bike that is pedal powered. It measures calories/watts. If thats what you are referring to, next time i use it i will take note of the watts in conjunction with my average HR on the polar H7. The Bike has a HR monitor on the handle bars but its wonky and cuts in an out quite often so not reliable.1 -
Look at my previous post. Your average calorie burn is probably about 1/2 of what you are estimating.
The fact that you are using inflated exercise numbers and yet still losing weight just points out the inherent inaccuracies of trying to estimate calorie intake, exercise calories, and “movement” calories.
If that was the case, i would be gaining weight, or if i was lucky, just maintaining. I am definitely eating back more then 1/2 of what i am exercising.
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nytrifisoul wrote: »
Look at my previous post. Your average calorie burn is probably about 1/2 of what you are estimating.
The fact that you are using inflated exercise numbers and yet still losing weight just points out the inherent inaccuracies of trying to estimate calorie intake, exercise calories, and “movement” calories.
If that was the case, i would be gaining weight, or if i was lucky, just maintaining. I am definitely eating back more then 1/2 of what i am exercising.
There is more to the equation than exercise calories. When I initially lost 60 pounds, I looked back and calculated my average deficit. I had structured 1000 cals/day, but it worked out to 1875 per day for five months. Depending on how you count it, NEAT calories can make quite a difference.
But physiologically, you would have to be working at 9-10 METs to burn the calories you claim during your workouts. That is not impossible, but I could find no literature for the TC 100 at the speeds you say you are using that would support such a number. The reported numbers are 4-5 METs which would give the calorie numbers I referenced earlier.
You are making progress and happy with your choices, so I don’t want to belabor what is a more of an academic argument. But this is my area of expertise and so I like to make sure that others who read these comments have realistic expectations.
To end on a positive note, I do agree with your original comment that it is quite possible for an average someone weighing above 80kg and of above average fitness level to burn 700-800 calories per hour during exercise. You don’t have to be an elite athlete.4
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