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I find that seemingly equivalent workouts on my treadmill and my elliptical trainer results in the latter device reporting that I have burned almost twice the calories as the former. However as I tend to feel a lot more tired after running on the treadmill than the elliptical, I'm a little sceptical of the "calories burned" reading.

Shape magazine reports:

A recent study named the elliptical trainer the least accurate when it comes to calorie counting, with most machines overestimating your burn by 42 percent [...]

Is it true that elliptical machines are the least accurate and most elliptical machines overestimate calories burned that much?

Oddthinking
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user29308
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    A claim of "least accurate" seems meaningless to me. Just take any calorie-estimating device and make it less accurate, and you have a new "least accurate." – Flimzy Oct 10 '15 at 12:40
  • It is not unrealistic that you can burn more calories on an elliptical trainer than on a treadmill, since you on the elliptical trainer perform more work with your upper body. I do however regularly train on two different models of elliptical trainers from the same manufacturer and even those two are far apart in their calculation of burned calories. The older model ticks me in at 1000-1100 kcal/h and the new model at 1800-1900 kcal/h. I honestly never expected the measurement of the workout device to be anywhere close to accurate though. – Tor-Einar Jarnbjo Oct 10 '15 at 19:42
  • Tor: That is disappointing to hear. Have you performed a similar comparison of treadmill models? Thanks. – user29308 Oct 12 '15 at 07:59
  • It is disappointing that the workout equipment even tries to tell you how many calories you have burned, since it is physically impossible for them to measure it. The number they show you simply can not be anything but a very rough guess. The equipment can measure your output power, and may use further input like age and weight to better match statistical models, but the equipment has absolutely no knowledge about e.g. how efficient you can perform the exercise. – Tor-Einar Jarnbjo Oct 12 '15 at 10:01

1 Answers1

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There's lots of research into this, and it's not that simple.

In fact, there is even research into how people overestimate how simple it is!

Much of the research into the illiptical machine read-outs is aimed at improving the models, so they are more accurate, (or, as we see below, selecting the best models, so they are the ones you see in gyms) so we might predict that old machines would be less accurate than new ones.

In 2013, the US Navy looked into this for their training: *Accuracy of Calories Expended on 7 Commercially Available Exercise Machines: Validation for use a Cardio Alternatives for the Navy Physical Readiness Test

They found the accuracy depended on the amount of exercise:

Figure 1

In this diagram, the blue line is the ideal, and each of the other lines refers to a machine they tried. Anything to the left of the blue line is the machine underestimating. Anything to the right is an overestimate.

In a 2014 experiment, TESTING THE ACCURACY OF THE CALORIE TRACKER ON ELLIPTICALS, the experimenters only looked at one machine, and concluded "the calorie tracker on the Nautilus ellipticals are not an accurate form of calorie tracking for workouts." Reading between the lines, the elliptical trainer tended to overestimate, but this is not part of their conclusions, so should be treated with caution.

In a 2015 experiment, Do Elliptical Trainers Accurately Estimate Energy Expenditure?, undergraduates compared two machines, and found one was 2.7% underestimating and the other was 24.7% overestimating.

This 2015 paper, The relationship between body fat percentage and difference in caloric expenditure as measured by indirect calorimetry and estimated by an elliptical trainer is interesting further reading. It describes an experiment that failed to confirm some of the hypotheses, but its introduction covers a lot of interesting aspects the problem - that elliptical machines may be good for weight loss regimes, that their perceived exertion is lower than than might be expected. That the calorie readings are generally considered overestimates. That BMI levels may be important in getting accurate readings.

In summary:

  • I haven't shown that most elliptical machines overestimate by 42%. It isn't that simple.
  • I haven't shown that elliptical machines are the worst in accuracy.

In this way, I haven't directly answered the question. However,

  • Yes, elliptical readers tend to over-estimate.
  • Their accuracy differs between brands.
  • Their accuracy differs on the amount exercised.
  • Their accuracy may depend on body fat percentages.
  • There's a lot more to this, and there's plenty of interesting research.
Oddthinking
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  • I think that given the question this is the best answer we're likely to get. – Shadur Oct 10 '15 at 14:25
  • Thank you. That graph is very useful. Are you aware of anything similar for the accuracy of treadmills and treadmill models? – user29308 Oct 12 '15 at 07:57