Which is better?

PiffBrown

I exercise daily on a stationary bike that also gives out readings of calories expended vs. the time factor. For example, I rode 30 minutes today, and the reading was 277 calories. But if I go to the MFP exercise page and enter 30 minutes for stationary biking, it reads out as more than 400 calories. That's a pretty big difference. Which one should I trust?

yirara

Probably neither. 277 calories for half an hour of cycling is already a very high reading unless you really created a high power output. 400 is really taking the mickey. Did the bike display the power in watts? that might give you an idea on how reasonable your calorie burns are.

sijomial

No-one can know from the information given as both numbers are possible for different levels of fitness.

e.g. If you are putting out a modest 100watts then 180 net cals would be very close to reality but an exceptional cyclist (most likely a professional male cyclist) could be putting out 400 watts of power and burning 720 net cals.

If your bike displays power in Watts it could be very accurate. If it doesn't it's in the lap of the gods as there is a huge variation between different types and brands of stationary bikes.

I wouldn't consider using the MFP database guess as it has a huge flaw in that the estimate varies in line with someone's weight (based on METS) whereas calorie burns from a stationary bike correlate with fitness ability and intensity.

The bike's estimate is at least likely to be proportionate if not accurate.

IAmTheGlue

Both those seem high to me. I always go for the lower amount though.

For my 30 minutes on the exercise bike this morning I was only given 39 calories by my Apple Watch. I’m not going all out, sweating, out of breath… I literally use my exercise bike as a chair… like if I’m going to watch TV, play a game on my phone, drink my morning coffee, etc I pedal a medium speed, averaging 12-14 mph. I literally ride my exercise bike on and off all day, just whenever I sit down basically. I don’t know that it adds up to much and I don’t generally eat back my exercise calories, but I like to be in motion instead of sitting idle.

If you are busting your butt, sweating and out of breath, really working out hard it would be more calories burned of course.

sijomial

yirara wrote: »

Probably neither. 277 calories for half an hour of cycling is already a very high reading unless you really created a high power output.

@yirara
Disagree - 277 cals for half an hour isn't at all high for a regular, competant male cyclist, it's actually quite a modest power output c. 150w.
Even an old fella like me can sustain that level for many hours.

Without knowing anything about the OP's fitness level and how hard he tried it's all speculation for this particular person and exercise session but it's definitely not universally "a very high reading".

MostlyWater

My Stages bike is a pretty good bike but I take its metrics with a grain of salt. For a 45 minutes class, which I warm up for 5 or 10 minutes beforehand, I am told that I burn around 250-280 calories.

If you want to know what you're burning, you need more sophisticated equipment which takes into account your weight and your heart rate, etc. Otherwise, it's just an approximation.

sijomial

MostlyWater wrote: »

My Stages bike is a pretty good bike but I take its metrics with a grain of salt. For a 45 minutes class, which I warm up for 5 or 10 minutes beforehand, I am told that I burn around 250-280 calories.

If you want to know what you're burning, you need more sophisticated equipment which takes into account your weight and your heart rate, etc. Otherwise, it's just an approximation.

@MostlyWater
Sorry but you shouldn't be taking your weight into account for a non-weight bearing exercise. That would be a very poor approximation for many people - especially the overweight and not very fit which are over-represented here.
That's part of the reason not to use the database entry for estimates.
It would only be useful if someone wanted to know their gross calories including the cals they would have burned anyway in that timeslot but those calories are already accounted for when using MFP so you would be double counting.

Heart rate monitors are also no guarantee of better accuracy as exercise HR varies enornously between people and is particularly poor for interval training.

Ariennalee

These are not very accurate, either of them. It's unfortunate but your best bet is to assume they're high and only eat back part of those calories and then compare your weight change over several weeks based on your most accurate tracking. If you find your weight isn't changing as fast or as is changing much faster than you would expect based on calories in and calories out, you can start digging into your process for inaccuracies

NorthCascades

Ariennalee wrote: »

These are not very accurate, either of them.

You're saying that like it's a fact, but we don't know if it's true or not. Several people have asked the OP how the number was derived and they haven't answered yet, so we can't know how accurate it is. If it was from a power meter the maximum error is +/- 2.5%.

Retroguy2000

Presumably the bike estimates gross cals not net? i.e. in half an hour you might have burned 50 cals sitting on the sofa instead, so the net gain is less than reported just for that reason alone.

For me, my bike doesn't display watts, and reports cals about 85% of what MFP says for the same time. I subtract 10% from the bike's estimate and plug that in to MFP. I figure that partly accounts for that gross/net difference.

It's all a guess in the end for me, and I prefer to err on the side of not over-reporting.

NorthCascades

yirara wrote: »

Probably neither. 277 calories for half an hour of cycling is already a very high reading unless you really created a high power output. 400 is really taking the mickey. Did the bike display the power in watts? that might give you an idea on how reasonable your calorie burns are.

That's only 154 watts.

Kaitensatsuma

Depending on the stationary bike's software I'd trust it more than the MFP estimate as I'd estimate it has some basic but relatively consistent calculation based on the settings you've put in. It's likely much more of an informed estimate than MFP which likely uses a basic MET calculation

270 is close to an estimate for what I get on a half hour ride on my road bike, but I'm getting that number based off of MapMyRide which can be +/- 20-40% off, which suggests the stationary bike might be as well.

I wouldn't use calorie estimates as anything other than a formality to be honest.

cwolfman13

PiffBrown wrote: »

I exercise daily on a stationary bike that also gives out readings of calories expended vs. the time factor. For example, I rode 30 minutes today, and the reading was 277 calories. But if I go to the MFP exercise page and enter 30 minutes for stationary biking, it reads out as more than 400 calories. That's a pretty big difference. Which one should I trust?

Be conservative. 400 calories in 30 minutes would basically be a pretty exceptional...likely professional cyclist to put out that kind of sustained power. Depending on your fitness level and cycling abilities, 277 is quite possible as that is around 150W which would be easily sustainable by a person who rides pretty regularly with some effort...I'm an avid rider and that's around my "all day" power output. Around 75-100W is where many beginners find themselves as well as recreational cruisers.

sijomial

@cwolfman86
"400 calories in 30 minutes would basically be a pretty exceptional...likely professional cyclist to put out that kind of sustained power. "

Sorry but that statement is miles away from reality.

400 cals in 30 mins is only 222 watts - that is not even close to what professional male riders can do.
The top guys are putting out double that!
https://sportcoaching.co.nz/pro-cyclist-ftp-and-coggan-power-chart/

I'm a very ordinary 62 YO recreational rider (not even a good club rider) and my last FTP test was at 218w.

cwolfman13

sijomial wrote: »

@cwolfman86
"400 calories in 30 minutes would basically be a pretty exceptional...likely professional cyclist to put out that kind of sustained power. "

Sorry but that statement is miles away from reality.

400 cals in 30 mins is only 222 watts - that is not even close to what professional male riders can do.
The top guys are putting out double that!
https://sportcoaching.co.nz/pro-cyclist-ftp-and-coggan-power-chart/

I'm a very ordinary 62 YO recreational rider (not even a good club rider) and my last FTP test was at 218w.

I know what they can do...but someone just going for a run of the mill ride on an exercise bike and averaging 222 watts while they're watching the t.v. is probably pretty up there. I doubt the OP was doing an FTP test. I would think 222 watts average for even a very fit cyclist would be a strenuous effort and not done on a daily basis...and yes, a pretty easy effort for a pro. Just trying to be realistic here...I don't think the OP is doing the Tour de France anytime soon.

sijomial

cwolfman13 wrote: »

sijomial wrote: »

@cwolfman86
"400 calories in 30 minutes would basically be a pretty exceptional...likely professional cyclist to put out that kind of sustained power. "

Sorry but that statement is miles away from reality.

400 cals in 30 mins is only 222 watts - that is not even close to what professional male riders can do.
The top guys are putting out double that!
https://sportcoaching.co.nz/pro-cyclist-ftp-and-coggan-power-chart/

I'm a very ordinary 62 YO recreational rider (not even a good club rider) and my last FTP test was at 218w.

I know what they can do...but someone just going for a run of the mill ride on an exercise bike and averaging 222 watts while they're watching the t.v. is probably pretty up there. I doubt the OP was doing an FTP test. I would think 222 watts average for even a very fit cyclist would be a strenuous effort and not done on a daily basis...and yes, a pretty easy effort for a pro. Just trying to be realistic here...I don't think the OP is doing the Tour de France anytime soon.

I just don't see any need for hyperbole.
Describing the mid-range of what's possible as the sole preserve of pro riders shouldn't be taken literally but there's a good chance of uninformed readers of this thread not understanding that.
There's plenty of evidence of uniformed readers already in this thread!

Yes we can both speculate that daily workouts are likely to be similar easy or moderate workouts but we don't know that, or indeed anything except duration. Maybe the OP picked his hardest effort of the week as an example rather than a typical session? We can guess but we don't actually have to guess.

NorthCascades

Also, it's a lot easier to hold any intensity level for half an hour vs several hours. It's definitely not so rare as to be assumed impossible for a recreational cyclist to put out 220w for 30 mins.

Djproulx

A bit late to this thread, but will offer a couple examples from my last two rides in support of @sijomial's point about what is possible/typical for a regular recreational rider (like me, 64 years old) as well as @NorthCascades point about the reliability of power data as a measurement device.

Monday's ride duration was 53:05, 167W ave power, 531calories burned. (a fairly windy 15 mile ride, 16.8mph ave)
Today's ride duration was 2:07:02, 152W ave power, 1166 calories burned. (a 37 mile North/south loop, 17.3mph)

So these numbers seem very "average" to me in terms of power output, yet in both cases the calories/hr expended exceeded 500. These were just my typical weekday rides, not any kind of race output.