If you’re someone who constantly worries about how many calories you’re burning during your workouts, then this article is for you. You’re going to learn two important ideas about exercise and estimated calorie burn:
Here are 3 reasons why estimated calorie burn on cardio machines is probably incorrect:
Imagine that all you did all day was lay down and not move. Your body requires a certain number of calories just to maintain your current body weight. This is called your resting metabolic rate (RMR), and it refers to the number of calories your body uses just to keep you alive (breathing, organ function, etc.). Your RMR is a huge determinant of how many calories you need to consume each day.
Treadmills and other cardio machines include RMR within their estimate of total calorie burn during your workout. This means the calorie estimate you see on display is not just how many calories you have burned during the activity, but also the number of calories you burned by simply being alive during that time. This leads to an overinflation of how many calories you burned by exercising.
For example, if a 175-lb man exercises for 30 minutes at a moderate pace, he will burn around 270 total calories according to his machine. But to get an accurate count, he would need to subtract around 40 calories from the 270 to account for his RMR. That means the number of calories he burned was actually closer to 230 calories.
The greater your workout time and the heavier you are, the more overinflated the number becomes. If you rely on exercise to create a large caloric deficit, you’ll definitely want to take this overestimation into consideration.
Calculating an estimated calorie burn on machines is very difficult because individuals vary so widely. In order to correctly estimate caloric expenditure, many factors need to be considered. Your total energy cost during exercise depends on your weight, gender, age, height, amount of muscle, and current disease state.
Treadmills rarely take the aforementioned factors into account. If you are exercising on a cardio machine and neglect to input information on your height, weight, or age, your estimates will be very off. Then, the cardio machine will use a default runner based on a typical man weighing about 160-180 lbs. If you weigh less than a typical man, your calorie burn will be overestimated, and vice versa.
Exercise efficiency describes how many calories your body uses to do work. People who workout regularly and are very fit are more exercise efficient. That means they use fewer calories to do more work or exercise.
There are many factors that affect exercise efficiency that may also throw off the estimated calorie burn shown on a machine:
1. Muscle Fiber Composition – Fast twitch fibers are less efficient than slow twitch fibers. Thus your efficiency, and potentially the total number of calories burned will depend on your genetic disposition and your overall training history.
2. Exercise Technique – Improved technique leads to fewer extraneous body movements and increased efficiency.
Lets take a competitive swimmer vs. a person who rarely swims as an example. If asked to travel the same distance at similar speeds, the experienced swimmer would burn fewer calories due to smoother strokes and a better understanding of buoyancy, which makes the activity easier for him.
The same applies to cardio machines. Although cardio machines are less technical than swimming, your body adapts to the exercises you do regularly, making them easier over time. As you get better, you burn fewer calories doing the same amount of work.
A relevant example is using the handrails to hold up your body on a machine like the Stairmaster. Bracing yourself with your arms makes the activity easier, yet the machine fails to adjust for this measure.
3. Fitness Level – More fit individuals perform a given task at a higher efficiency because of decreased energy expenditure from non-exercise tasks such as temperature regulation, increased circulation, and waste removal. When you do specific exercises regularly (like running, using the stepmill, or rowing), you improve your cardiovascular fitness level and your muscles adapt to that exercise.
Improved fitness means that you burn fewer calories, unless you continually increase the challenge.
All of this is not meant to deter you from using cardio machines in your quest to lose fat. Increasing your exercise efficiency is not necessarily a bad thing when it comes to fat loss. Usually, an increase in efficiency comes with an increase in ability. For example, more efficient exercisers can usually run further and faster, and push themselves harder.
In fact, the best fat loss strategies generally encourage you to increase the intensity of your cardio workouts, not necessarily the duration.
Overall, there’s too many factors that affect your individual calorie burn during exercise to get an accurate estimate from a cardio machine. If you really need to know the number of calories you burned during your workout, you might want to consider using a fitness tracker like a Fitbit, but keep in mind that it has its own limitations.
At the end of the day, if you want to lose fat and keep it off long-term, it’s critical to get your diet in check so that you don’t rely on the “burn it off” mentality. You can’t out-train a bad diet. No amount of exercise will get you a lean and strong body if you’re not paying attention to your nutrition.
Also, consider weight training or interval training if you’re serious about burning fat. Throw in steady state cardio between your strength training days if you don’t want to limit your workouts to strength training. All in all, remember – don’t trust the machine.
For more ideas on the best nutrition, exercise, and lifestyle strategies to lose weight, check out these 101 Proven Tips to Lose Weight Fast.