The reliability of these calculations in figuring out the volume of calories you expend during a workout depends on your size, body composition, workout intensity, and fitness level.

When the machine does not ask for your body weight, you can be sure the calorie count isn’t accurate.

Individuals who weigh less burn fewer calories than people who weigh more when doing otherwise equivalent workouts.

If the machine does ask for your weight, it is giving you an approximate count of calories burned. the reliability of the numbers varies by manufacturer and depends on what formula the machine uses.

Excercise machines, like a lot of website calorie calculators, use various formulas to calculate the approximate number of calories burned.  

A number of are more exact than others – a number of sites have you plug in the weight, exercise mode, and time to calculate your caloric expenditure.    

For a rough estimate, this is fine. Nevertheless, you could also be interested in calculating more a more precise picture of calories burnes; here’s a partial listing from a well-respected text, Exercise Physiology, by McArdle, Katch, and Katch   

Activity    Calories/lb/minute

Aerobics    

Moderate    0.065

Vigorous    0.095

Step    0.07

Cycling    

5.5 mph    0.033

10 mph    0.05

13 mph    0.071

Jump rope    0.06

Running    

11 min/mile    0.07

8.5 min/mile    0.09

7 min/mile    0.102

6 min/mile    0.114

Stairclimber    

Moderate    0.07

Vigorous    0.09

Stationary Cycling    

Moderate    0.055

Vigorous    0.09

Note – “Moderate” and “vigorous” are not specific terms. But typically “moderate” means you will notice some increase in your breathing or heart rate, and “vigorous” means you will notice a large increase in your breathing and heart rate.    

For example, moderate activity might include brisk walking, playing catch, or yoga.

Vigorous activity might include running, swimming, basketball, or soccer.

Also consider that a person who’s a high percentage of lean body mass will spend more calories than a person with a greater fat mass, because lean tissue is more metabolically active.

In addition, as an athlete adapts to a certain mode of exercise, the muscles become more efficient and work becomes easier, causing slightly fewer calories to be used up.

Now, you are able to keep your muscles guessing by cross-training or switching activities.

Technique also matters – for example, when you’re leaning on an elliptical machine (putting your weight on your arms), you’re decling your body weight load and burning far fewer calories than the machine says. the same holds true for a treadmill.

You are better off setting the machine at a lower intensity and swinging your arms at your sides (touching the side bars occasionally for balance).

When you would prefer to put energy your into working out, rather than mastering the myriad ways of calculate calories burned, you can simply keep some general exercise guidelines in mind

• Participate in moderate exercise for at least 30 minutes, five or more days each week

• Participate in vigorous physical activity for at least 20 minutes, three or more days weekly