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The short answer is no. But, we will look at why these calories are inaccurate, how you can get a better estimate of calories burned, and if your fitness wearable is more accurate than a treadmill or other cardio machine.
Calorie burn estimates are essential for exercise to calculate caloric intake and calorie expenditure for weight loss or weight gain. Treadmill calorie counters could be off by hundreds of calories, adding up over time to drastically impact your goals. Even the best treadmills could be wrong, but that doesn’t mean you are in for a bad workout.
Key Points
- Treadmill calorie counts are probably inaccurate. A treadmill calorie count could be spot-on or an educated guess. Most calorie counts are based on some science but may not represent what is happening in your body.
- Fitness trackers may be more accurate but are not 100% trustworthy. Fitness trackers often measure heart rate which helps estimate calorie burn, but heart rate tracking is not 100% accurate. Heart rate may also be affected by factors unrelated to calorie burn.
- Other measures may be more helpful for improving fitness. Tracking your progress toward a goal (like running a mile), rating workouts on RPE, or trying to beat yesterday may be more helpful than measuring your workout difficulty by treadmill calories.
- It’s hard to track calories. Accurately measuring the calories you burn or calories contained in food requires advanced instrumentation that most of us do not have.
How Accurate Are Treadmill Calorie Counts?
Treadmill calorie counts are only as accurate as their calculations and the information they take in. If you get on a treadmill and press the quick-start button (without putting in any of your demographic information), the treadmill provides you with the same number that it shows to anyone else who works out at the same speed and for the same time. However, it’s unlikely that two people burn the same number of calories during the same workout. So many individual factors go into determining the calories burned: your body composition, age, weight, height, gender, hormones, and more.
Even if your treadmill does take in some information about you (age, weight, and height), that’s only a small portion of the factors mentioned. When I input the same run information into multiple different calculators (similar to those a treadmill uses), I received many different calorie estimates: 792, 827, 866, and 873. My Garmin estimated my calorie expenditure to be 820. It’s reassuring that these numbers are less than 100 calories different, but unfortunately, I have no idea if any of these numbers are remotely accurate for me. When I use a calculation that does not factor in my weight, I come up with 1100 calories for the same run. Thus, calorie estimates could be off by hundreds of calories.
If you are painstakingly counting calories, these errors in calorie estimation can be very frustrating. You can use treadmill calorie counts to compare workout intensities on the same machine. A faster, steeper, or longer workout will have a higher calorie burn.
Practical Applications for Using Treadmill Calorie Counts
You could ignore calorie counts altogether. That’s a valid option. It’s what I do most of the time. Instead, I pay attention to general trends in my weight, exercise, food, and sense of well-being. If my weight is higher or lower than I would like, I adjust my food intake and choices. I evaluate changes in my activity level. This big-picture approach can help the health-conscious individual who is overwhelmed by these calorie count inaccuracies or tends to obsess over them.
Better Ways to Track Your Workout Intensity
- ACSM Guidelines: The American College of Sports Medicine (ACSM) sets guidelines for weekly exercise. For cardio, adults should aim for a minimum of 150 minutes of moderate exercise (30 minutes across 5 days) or 60 minutes of vigorous exercise per week (20 minutes across 3 days). Additionally, strength training should be done at least 2 days per week.
- Setting a Goal: Setting a personal goal of running a certain distance, beating a certain time, preparing for a hike, or another walking/running goal can add direction and purpose to your treadmill workouts.
- Varying Intensity: One of the biggest beginner mistakes on the treadmill is to always train at a moderate and steady pace. Adding bursts of speed or incline will help you burn more calories, reach your goals, and beat plateaus.
- Keep a Journal: Instead of tracking your treadmill calories, track your rate of perceived exertion (RPE), mindset during your workout, pace, time, total distance, and other thoughts and feelings toward your session. Keeping a journal may help you reflect and improve upon past training sessions instead of growing stagnant.
- Avoid Over-Rewarding Yourself: Seeing a calorie count can make it tempting to reward yourself with an extra treat. While indulging is great in moderation, the inaccuracy of treadmill calorie counts means we cannot use it to guide our eating habits. Focus on developing sustainable eating habits incorporating enjoyable foods rather than fixating on the next cheat meal.
Can I Trust My Phone or Fitness Tracker Calorie Counter Instead?
Unfortunately, even wearables that track heart rate and advanced walking and running dynamics could be wrong about your calorie burn. Factors such as fatigue, sickness, and temperature could increase your heart rate without a coinciding change in your calorie burn.
Many fitness apps and fitness trackers calculate a calorie burn by estimating your current oxygen consumption based on a heart rate reading that is not 100% accurate. That’s a lot of estimating, which could create great inaccuracies if any of those estimates are just a little off. Even when fitness trackers use more advanced features like running dynamics, they don’t reach a lab-quality measurement. While fitness technology is improving, we haven’t reached 100% accuracy yet.
How Is Caloric Expenditure Calculated?
Formulas
Many different formulas have been created to estimate caloric expenditure during exercise. These formulas typically require age, height, weight, and gender inputs. More advanced formulas may need more information. What all formulas have in common is that they do not directly measure your caloric expenditure. There are always factors they cannot account for. Treadmill manufacturers rarely disclose which calculations they are using, so there is no way to know how confident you can be in your treadmill’s estimate of calories burned.
Indirect Calorimetry
For a more precise estimation of calorie burn, you need indirect calorimetry.
In a lab setting, an exercise physiologist or other qualified professional would put a mask over your face attached to a metabolic cart. A metabolic cart analyzes the gasses you breathe out. This analysis tells the machine how much oxygen you are consuming and how much carbon dioxide you are producing. From this measurement, we can calculate how much carbohydrate and fat your body is using for fuel.
Protein is neglected because your body avoids burning protein for fuel and will only do so if other energy sources are scarce.
Once we know the ratio of oxygen and carbon dioxide breathed out (RER), we can calculate how many calories are burned per minute at a set level of oxygen consumption. These calculations also use your body weight to calculate calorie burn.
Takeaway: Indirect calorimetry better represents the calories burned during rest or exercise. It requires an accurate body weight measurement, knowledge of the gasses available in the atmosphere, and measurement of the gasses exhaled with each breath.
Direct Calorimetry
The most accurate measure of caloric expenditure is also the least practical. You must be confined to a closed chamber to directly measure how many calories you burn at rest or during an activity. Inside this chamber, your output thermal energy is measured. This measurement of calorie expenditure is the most accurate.
This method works because calories are burned. We produce heat when using energy. It makes a lot more sense why exercise makes us hot!
Takeaway: Direct Calorimetry is the most accurate calorie measurement.
So, What Does That Mean For Treadmill Calories?
Your treadmill is probably wrong because it is based on demographic information that may or may not be right. That information is then plugged into a formula based on an indirect measure based on a direct measure. That’s a lot of steps away from being an accurate representation of calorie burn. But, treadmill calorie counts may help compare your workout intensity to previous workouts and subsequent workouts.
What Factors Affect Caloric Expenditure?
- Age
- Weight
- Body Composition
- Height
- Gender
- Hormones
- Food Intake
- Health
- Fitness
Treadmills don’t have all of this information. They might collect some of it. They may estimate the rest by tracking your heart rate if you wear a compatible monitor.
The Other Parts of the Calorie Equation: Caloric Intake and Basal Metabolic Rate
If you are curious about the accuracy of your treadmill calorie count, there’s a good chance that you are also tracking your intake of calories. In addition to our calories in and calories burned during exercise, we also need to factor in the calories we burn to stay alive–our basal metabolic rate or resting metabolic rate.
These numbers are useful for anyone trying to gain or lose weight but aren’t as straightforward as you might hope. They are also estimates.
Caloric Intake
For many of us, counting calories isn’t as much about being accurate as it is about making the math work. For example, you see that 4 small cookies are a serving. You want to eat one serving. So, not only do you see which of the cookies is the largest, but you also count the two cookies stuck together as one cookie. I’ve done it.
For the serious calorie counter, you weigh your food. Gram by gram, you measure it out. That’s a much more accurate way to do it, but it has its limitations. It can lead to obsessive behavior, it limits going to restaurants or eating at a friend’s house, and no matter how well you measure, food labels might be wrong.
The only way to directly measure the calories in your food is to place it in a bomb calorimeter. The food is burned inside a chamber surrounded by water. The water temperature increases as the food burns. We then measure how much the temperature of the water is raised. Unfortunately, once the food is burned, you can’t eat it.
Even with the best measurements of calorie intake, there are variables beyond our control. Some foods require more calories to digest than others. This is called the thermogenic effect of food. Our bodies’ abilities to digest food and the thermogenic effect of different foods are almost impossible to account for.
Basal Metabolic Rate
Your basal metabolic rate is the amount of calories you burn to stay alive. A related term, resting metabolic rate, is the amount of calories you burn while awake in a resting state. There are tons of online calculators to estimate BMR and RMR. Add a 0 to your weight in pounds for a rough estimate. For example, a 200-lb person would roughly have a 2000 kcal resting metabolic rate.
Individual differences still exist. When I was completing my undergraduate degree in exercise science, other students would go into the exercise physiology lab and sometimes leave with shocking results. Sometimes their resting metabolic rate was much lower than the formulas estimated. For others, it could be much higher.
The calculations used to estimate BMR and RMR are based on averages. You could be an outlier in one direction or the other. The further you are away from the average, the more frustrated you might get with calorie counts based on these averages. Your results won’t align with what the numbers say they should.
Frequently Asked Questions
Am I burning more calories than the treadmill says?
Maybe or maybe not. Your treadmill could be overestimating or underestimating your calorie burn. The treadmill calorie counter could be off by a few calories or even hundreds of calories.
Is 400 calories on a treadmill good?
400 calories is a good amount to burn for a workout. The ACSM recommends 150 minutes of aerobic activity per week. 400 calories takes around 30 to 50 minutes to burn depending on your exercise intensity. So you need about 3 to 5 similar sessions per week to reach the ACSM guideline. That’s a great routine!
What’s a good amount of calories to burn on a treadmill?
A 30–minute workout could burn 200 to 500 calories depending on your training intensity. That’s a great range to shoot for, but even a light to moderate 10-minute walk on the treadmill is better than nothing. Treadmill calorie counts may not accurately represent your caloric burn, so consider aiming for a time, distance, or effort goal instead.
Why do I burn so little calories on the treadmill?
You may not be burning many calories on the treadmill because the calorie counter is inaccurate, your training intensity is too low, or your training strategy needs revision. To burn more calories on the treadmill, try a HIIT workout that incorporates faster intervals or incline training.
Don’t trust the number of calories shown on the treadmill, especially if you are seeing better indicators of your fitness and health improving. Weighing yourself, ranking workouts by difficulty, and conquering other target goals may be more telling and effective for tracking your progress. Be wary of calorie counting and weight tracking if it promotes obsessive and unhealthy behaviors for you.