We all do it, we look at how many calories we’re burning on the treadmill, elliptical or stair climber at the gym. It gives us a little encouragement when we just want to know that this sweat sesh is worth it. But, how accurate is that calorie-counting pixie that’s hidden inside that machine? I hate to disappoint you, but it’s about as accurate as your local weather man!
These machine-generated calories are in fact just a rough estimate. While some types of cardio machines are more accurate than others, none of them will be 100% accurate. In general, they overestimate your calorie burn by about 20% because they can't account for all the individual factors involved in calorie-burning.
Here’s a scenario; two stair climbers side by side and a 6 ft 200lb bodybuilder clambers up one, while a 5ft 110lb ballerina nimbly hops on the other. Both perform 20 minutes of stair climbing at level 6. When they're finished, both machines show that both the bodybuilder and the ballerina have burned 200 calories.
Do you see where I’m going with this? The differences in their height, weight, gender and muscle mass makes this highly unrealistic. Here are some additional factors to consider:
Fitness level: Whether you're just starting an exercise program or changing activities, the newer you are to it, the more calories you will burn. As you become more efficient and fit, you will burn fewer calories doing the same activity for the same period of time.
Body composition: When you start exercising, it's likely that you will have more fat than muscle mass, so you will burn fewer calories at first. As you build muscle, your body becomes more efficient and will burn more calories for the same amount of exercise.
Body size: When two people weigh the same, the one with a larger frame can burn more calories.
Age: Some machines factor in your age and others don't. Nonetheless, as you grow older, you may not burn the same number of calories as you did when you were younger due to a reduction in muscle mass and an increase in body fat. You can make up for this by increasing either your workout time or the intensity of your routine.
Whether it's cardio equipment at your local gym or the fitness tracker there on your wrist, it's best to take the calories burned readings with a grain of salt. It's fine to use the numbers as a benchmark for your workouts, but don't use ‘calories burned’ as an excuse to consume more calories. This may lead to gaining weight despite your best exercise efforts.
Having a general idea of how many calories you're burning during exercise is a good way to manage your health and weight. Just keep in mind that any of the calorie counters are probably overestimating what you're actually burning. How you feel after the workout is more important.