Many of us rely on the calorie counters on cardio machines like treadmills and ellipticals to track our workouts. But how accurate are those calorie counts really? Can we trust the numbers we see on the display?
How do calorie counters on cardio machines work?
Treadmills and other cardio machines estimate your calorie burn using an algorithm that takes into account different factors like:
- Your weight – Heavier people burn more calories than lighter people when running at the same speed.
- The speed you’re running or walking – The faster you go, the more calories you burn.
- The incline or resistance level – Running or walking on an incline burns more calories than doing it on a flat surface. The same goes for increasing the resistance on an elliptical.
- Your heart rate – The higher your heart rate, the more calories you’re burning.
- The duration of your workout – The longer you workout, the more calories you burn.
The machine then takes these factors and plugs them into equations to estimate your calorie expenditure for that workout. Different brands may use slightly different formulas.
How accurate are treadmill calorie counters?
Research has found that the calorie counters on cardio machines are often inaccurate, sometimes overestimating or underestimating calories burned.
For example, one study published in the Journal of Sports Science & Medicine compared the calorie estimates from treadmill counters to the calories measured by a metabolic cart during running on a treadmill.
They found that the treadmill overestimated calories burned at lower intensities (by up to 10%) but underestimated calories burned at higher intensities (by up to 12%).
Another study published in the International Journal of Exercise Science looked at elliptical trainers. Researchers compared the machine estimates to calories measured through indirect calorimetry.
On average, the elliptical calorie counters overestimated calorie burning by 42%. However, some machines were better than others.
So why the inaccuracy? There are a few reasons:
1. Estimated vs. measured data
Treadmill counters rely on estimated data like your weight and the machine’s estimate of your effort level. But they can’t precisely measure important details like:
- Your exact fitness level and metabolism.
- Minor variations in your effort, like if you’re gripping the handles tightly or pumping your arms.
- How much you weigh exactly at that moment, which can vary throughout the day.
Measuring calories burned precisely requires special equipment to analyze oxygen and carbon dioxide exchange during exercise. Treadmill counters only provide a rough estimate.
2. Self-reported user data
Many of us simply accept the default weight that’s programmed into the machine already. But if that number doesn’t match your current weight, the calorie calculation will be off.
Entering inaccurate data for your weight, age, and gender can further throw off the estimate.
3. Different treadmill brands and models
There’s no standard formula used by all manufacturers for calculating calories. The algorithms can vary significantly between brands and models.
Newer machines may provide more accurate estimates than older models. High-end commercial treadmills found in gyms are generally more sophisticated than cheaper home models when it comes to estimating energy expenditure.
Tips for getting better calorie estimates
While treadmill counters aren’t perfect, you can take steps to improve their accuracy:
Enter your stats correctly
Make sure to program your current weight, age, gender, and if possible, your maximum heart rate.
Don’t accept whatever numbers were already plugged in. Entering the data correctly makes the calorie math more precise.
Use handrails sparingly
Gripping the handrails reduces the amount of effort your body has to exert, so the machine will underestimate calories if you’re holding on. Use the rails only when needed for balance or support.
Check your heart rate
Look for a machine that can scan your heart rate through sensors in the handles or a chest strap. This provides more accurate data to the algorithm.
If the counter seems way off, your measured heart rate can confirm if you’re really working out at a higher intensity than the machine calculated.
Combine with other metrics
Don’t rely solely on the calorie counter to measure your workout. Look at the full picture by also tracking your heart rate, speed, distance covered, and subjective level of exertion.
Cross-check the machine’s calorie estimate with calories calculated through mobile apps or wearable devices.
Focus on the trend
The exact calorie numbers may be off, but the counter can still reveal helpful trends over time. You can see if you’re burning more calories from workout to workout at the same settings.
Just don’t fixate on the precise calorie amount for each session.
The bottom line on treadmill calorie counters
Research shows treadmill calorie counters are often inaccurate and shouldn’t be taken as gospel. The estimates tend to be off, especially at higher and lower intensity levels.
However, the counters still provide useful insight into your workouts. Here are some key takeaways on their accuracy:
- Don’t expect precision – The estimates are rough ballpark figures, not highly accurate lab measurements.
- Enter your stats carefully – Providing incorrect user data introduces more errors.
- Consider them one metric – Combine calorie estimates with other stats like heart rate and perceived exertion.
- Track trends over time – Look for increases in estimated calories burned as your fitness improves.
- Upgrade for better accuracy – Invest in a higher-end commercial model if precision is vital.
While calorie counters on treadmills have limitations, they can still give you valuable feedback on the intensity and progression of your running or walking workouts when used wisely. Just avoid fixating on the exact numbers.
Frequently Asked Questions
Why are treadmill calorie counters often inaccurate?
Treadmill calorie counters estimate calories burned based on limited data like your weight, speed, and incline. They can’t precisely measure details like your fitness level, effort intensity, and real-time weight changes throughout the day. Relying on self-reported user stats also introduces errors.
Should I completely ignore the calorie estimate then?
No, the estimates can still provide useful insights into your workout intensity and progression over time when viewed as a rough estimate. Just avoid fixating on the precise calorie amount. Combine the estimate with other stats for a more complete picture.
How much error is typical for treadmill calorie counters?
Research has found errors ranging from 10-42%, depending on the study and intensity level. Counts tend to be more inaccurate at very high and low intensities. Newer commercial models tend to be more accurate than older or home models.
Is there a way to get more accurate calorie counts?
Using additional devices like a heart rate monitor, fitness tracker, or mobile app can provide a second estimate to cross-check against. Metabolic cart testing in a lab offers the highest accuracy but isn’t practical for daily training.
Should I update my weight in the machine’s settings periodically?
Yes, you should update your weight regularly, such as once a month or whenever you notice significant weight changes. Having your current exact weight in the machine’s algorithm helps improve accuracy.
Treadmill calorie counters can be useful tools to estimate your workout intensity and track progress over time. However, research clearly shows the counters are often inaccurate, sometimes substantially so. For a single workout, view the calorie estimate as a ballpark figure rather than a precision measurement. The most important thing is the quality of your training, not the exact calorie amount. By entering your stats properly, combining calorie data with other metrics, and not fixating on the numbers, you can still get valuable insights from the counter. Just don’t expect laboratory precision from this convenient but imperfect tracking tool.