Calories Burned and Cardio Equipment

Cherisehirz

Hey Everyone,

I've heard that cardio equipment overestimates your calories burned by 30%. Does anyone know if this is true? At my gym, I am able to enter my weight for more "accurate" counts, but does that truly make them accurate? It's disappointing to think that the machine is reading 700 calories burned, but really, it could possibly only be 490, which changes A TON of factors in planning and preparing meals etc... when trying to lose weight.

What are your thoughts? Thanks!

LindsayT2012

That is why I bought a heart rate monitor so that I could have and accurate count. THe machine is usually 50 calories off for me so its not to bad of a drop

Athena413

Most cardio machines are defaulted to a 150# male. I'm not male OR 150# and when I compare my heart rate monitor to a machine, machines underestimate mine. I don't trust machines at all, but that's just me. I suggest investing in a good heart rate monitor if you want a good reading.

wolfchild59

If you're a woman especially, never trust the machine info, even if you enter age/weight. They seem to be mostly calculated for guys. For me, when comparing to my HRM, the machines are always much higher, typically in the hundreds. I used an elliptical at the gym once that, with my age/weight entered, for a 50 minute session hit 1000 cal and cycled back around to 0 and started counting up again! I actually burned 458 cal, according to my HRM.

Smittyinthesun2

You need to set the machine to your weight, you'll notice when you get on that almost all are set to 150 pounds, so enter your weight before you workout.

sandy2006

At my gym one type of elliptical said I burned 210 and my HRM said 153. A different type elliptical said 100 and my hrm said 189. BIG difference

AdamB311

Reading all this, can anyone recommend a good HRM for both the gym and out running myself? I've always taken down the calories machines say and used that for my daily food count

Azdak

Machines are set up to measure the actual "work" you are doing. In order for them to be at all accurate, you need to be able to input your weight.

All steady-state cardio execise has a fixed energy cost, according to the intensity of the work being performed. In other words, walking at 3.0 mph on a treadmill has an energy cost of 3 METS, riding a bike at 50 watts has a certain energy cost. That energy cost is the same for everyone, for the most part.

Calories expended depends on the energy cost x body weight.

HRMs work on a completely different principle. During steady-state aerobic exercise, there is a calculable relationship between % of HR max and % VO2 max. Top-level HRM manufacturers like Polar have tweaked and research the mathematical relationships to the point where, with the proper set up info and under the appropriate exercise conditions, they can estimate caloric expenditure based on heart rate.

For simple aerobic movements, eg walking or running, there are long-established, validated equations that predict energy expenditure based on workload. These equations are programmed into the machines.

Each method has pluses and minuses. For simple movements--again like walking on a treadmill--the machine calories could easily be more accurate than an HRM. That's because the machine is measuring ACTUAL work performed, not estimating intensity second-hand like an HRM.

If there are not established energy-prediction equations available for a cardio movement or machine, or if the manufacturer did not go to the effort of trying to accurately program the machine, then the machine displays are not very good. Cross trainers are probably the least accurate because the movements are all different -- so there is no common equation available. Unless the manufacturer sets up their own validation research program, they usually just take something related -- like running at the same speed suggested by the pedal movement -- and use that.

You cannot make the broad statement that "all machines overestimate calories" or that "the only way to an accurate calorie count is with an HRM".

Some machines are very accurate and many HRMs are just toys--plus even many quality HRMs are set up incorrectly with the wrong HRmax, etc.

In the end, everyone should realize that estimating exercise calories is a rough guess at best. It is wrong to expect precision from any source or to include exercise calories in an eating plan as "absolute truth".