Wearable technologies can be helpful workout tools for people of all ages.
Whether you are an elite athlete or a Superwoman looking to live her healthiest life, wearable technologies can be an accessible way to plan, modify, and measure workouts.
While wearable heart rate monitors are largely accurate when it comes to heart rate, are they accurate for tracking calorie expenditure?
Today, we’ll dive into the science of heart rate monitors and calorie expenditure tracking.
Here’s what you need to know:
Reasons to Track Calorie Expenditure
Before getting into the accuracy of calorie tracking, it’s important to note the reasons for wanting to track calorie expenditure. How can calorie tracking play a role in helping you become the Superwoman you want to be?
- Assess your energy balance, or how many calories you intake vs output. To lose weight, you must be in a calorie deficit.
- Avoid under-fueling your body. When you exercise, you tear your muscles down. To see muscle and strength growth, you must properly fuel your body.
- A reminder that living requires calories. Seeing total calorie expenditure throughout the day serves as an important reminder that everything we do burns calories, not just workouts.
Do Fitness Trackers Accurately Track Calories Burned?
Overall, heart rate monitors are surprisingly good at measuring heart rate. The research team at Standford University School of Medicine found that six out of the seven top wearable trackers accurately measured heart rate within 5 percent.
If the devices could measure heart rate correctly, were they able to accurately track calories?
Unfortunately, the Stanford evaluation reports that “ none of the seven devices measured energy expenditure accurately, the study found. Even the most accurate device was off by an average of 27 percent. And the least accurate was off by 93 percent.
Consumer devices, like the Apple Watch, PulseOn, Fitbit Surge, etc simply aren’t held to the same standards as medical-grade devices. Each device uses a different algorithm to calculate energy expenditure, and there’s a good chance that those algorithms don’t take each individual into consideration. It would be extremely difficult to create an algorithm that would be accurate across a wide range of people.
What About Polar?
The Polar chest-strap tracking devices are the gold standard for heart rate tracking. They outperform wrist-worn trackers for heart rate accuracy. So, can the Polar H7 hold up when it comes to tracking calorie expenditure?
A 2010 study from the British Journal of Sports Medicine found that the Polar Activity watch held up to the accepted 10% error margin for calorie tracking. However, a 2018 study in Medicine and Science in Sports and Exercise found that the Polar H7 chest strap did not fall in the acceptable accuracy range for tracking calorie expenditure.
However, there has been a promising example that suggests we may be able to measure calorie expenditure more accurately in wearable devices. In 2010, researchers studied the Polar S810i heart rate monitor. They found that the tracker was not accurate for low-intensity exercise, but that it was accurate for moderate exercise. For the Polar heart rate monitor to provide accurate measures of calories, it had to have the user’s V02max programmed.
Factors that Influence Calorie Expenditure
It’s very difficult for consumer wearable technology to accurately estimate calorie expenditure. While tracking heart rate is straightforward, tracking calories is not. Essentially, the devices must estimate calorie expenditure based on your heart rate and some other approximations.
Here are some of the factors that influence calorie expenditure:
- Age
- Sex (females have a lower energy expenditure per unit of weight than males)
- Body composition
- Body weight
- Hormonal status
- V02max/ fitness level
Be Cautious with Wearable Technologies and Calorie Tracking
While heart rate trackers are pretty accurate for tracking heart rate, they are not nearly as accurate for tracking calorie expenditure. Overall, it’s quite difficult to mass-produce a product that accounts for the many individual factors that influence calorie expenditure. However, there have been promising advances that suggest we will be able to make wearable options that fall within the 10% margin of error for consumers.
At the moment, it’s best not to rely totally on wearable technology to determine your calorie expenditure. While it can give you a rough idea, you should not use it to make decisions about your fitness or nutrition.
One helpful tool for estimating your resting metabolic rate is the JOC Calorie Counter. With this calorie counter, you can enter your personal details, goal weight, and more. The calorie counter then provides you with an estimate of how many calories to eat per day to meet your goals.
The Calorie Counter is just the beginning. It can give you a great starting point, but the best way to meet your body transformation goals is with the help of an expert. The JOC team is here to help you become the healthy, confident Superwoman you are through proven fitness, nutrition, and mindset programs. Learn more about how JOC can help you or get started today by contacting our team of experts.
