Stationary bike calorie burn discrepancy

I have the same question. A 60 min workout on a Cybex 750R (recumbent) with my correct weight entered told me when I finished that I burned 250 calories but when I enter MFP routine (stationary bike at 12 to 14 mph for 60 min) it said I burned 800 calories. Quite a difference. Which is correct??

Honestly they are all just painfully bad estimates. One person sitting on a bike can and will burn a different amount than another person on the same bike with the same settings.

It's probably best to take the bikes estimate as "closer" since it knows the specific intensity you rode at but even then take it with a grain of salt.

Weight loss is a huge business for everyone but the overweight. Foods are nearly always labeled to err on the side of lower calories / fat and exercise equipment often takes the best case caloric burn for their estimates. People will spend more for a bike that lies to them about the calories burned just as they will pay more for food that lies to them about the calories inside it.

While it's nice to have some guide posts, the reality is that you should try to get as much exercise as you healthily can while you eat the most nutritious foods you can only in the quantities needed to sustain your physical needs.

sounds like you agree with me about trusting the bike and not MFPs estimation. 100 calories in 20 minutes is a huge difference!

I think the biggest issue, for those of us who want to be all scientific and calculate every little calorie in and out is that both the exercise machines and MFP sort of double dip a little by double counting your normal metabolic rate. The exercise equipment wants to know your weight so it can figure out your RMR and then up the calories per hour by what ever you would burn if you were just sitting on the gym floor looking at the machine.

The problem comes up in that MFP already has this information in there based on your stats (i.e. Goals / Calories Burned / From Normal Daily Activity) but still seems to include the combined numbers when adding calories burned for any given exercise.

I mostly log the exercise just to have the record of what I am doing and assume that the math behind it is fundamentally flawed.

why is there such a big discrepancy between what MFP tells me I burned doing 20 mins on a stationary bike (244) vs what the bike tells me (144)? Both MFP and the bike know I am 150 lbs- and I use a resistance of 14-17 so I am not just going for a leisurely stroll. Its hard work! I believe the bike (144) before MFP (244) but was just curious if anyone else noticed this?

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It's hard to say based on the accuracy of the device measuring you. It could be correct - if 14-17 is enough resistance that you are producing high watts and your heart rate is up there (say 155-170), then yes - you'll burn more calories. I think MFP uses speed as a factor which doesn't include resistance (watts), cadence, etc... . As an example, I can do a killer mountain bike ride with very tough climbs and can be a thoroughly exhausting workout, but because mountain biking speeds are slower than riding on pavement by quite a bit - MFP will way undercut the amount of calories that my chest strap HR monitor and power meter report I have burned.

I would go with somewhere between the lower number and higher number (not knowing what resistance of 14-17 equates to in terms of HR and Watts produced). What kind of stationary bike (brand and computer display) are you using? Maybe there is some information available on the internet about the accuracy of that particular model.

Either way, 20 minutes is a very short session and traditionally in cycling is a good warm-up amount of time with lower resistance before you turn on the power. Every exercise bike measures through a wide array of guesstimates. So you may have to just be content to be a bit "in the dark" with regard to the machine you are using.

Suffice it say, you're burning some calories. ;-)

I don't think either are accurate. MFP and the stationary bike both seem to be excessive in comparison to what I get on my Polar HRM. And I have a great trust in the Polar in my running so assume it is as accurate on the bike.

To be on the safe side I'd take the lower # anytime. The worst thing we can do is delude ourselves.

My experience with MFP's estimates is that they are wildly inflated for most people. Machine estimates are usually better, but I've still had them come in both high and low. I currently use a heart-rate monitor to keep track of my average heart rate for an exercise session. Then I record all of my exercise on a spreadsheet that converts that average heart rate into net calories burned, but there are also a number of online calculators that do the same thing. The Heart Rate Based Calorie Burn Calculator on the shapesense website calculates out gross and then net calories burned and appears to be using the same formulas I use in my spreadsheet.

TL;DR: Heart Rate Monitor Estimate > Machine Estimate > MFP Estimate