One of the challenges for those who exercise and watch what they eat in an effort to lose weight is knowing exactly how many calories are burned during exercise. There are numerous apps and wearable devices, such as the Apple Watch and Fitbit, that claim to show the number of calories burned during a workout. The problem is that those calorie counting systems are often highly inaccurate, making it difficult to count calories in and calories out with accuracy.
Engineers from Stanford University have developed a new calorie burn management system that is described as small, inexpensive, and accurate. One of the most interesting aspects of the device is that people can make the wearable device themselves. Researchers on the project say that wearable smartwatches and smartphones can be off by as much as 40 to 80 percent when it comes to counting calories burned during activity.
The system developed at Stanford averages only 13 percent error. Researchers tested their compact system with a diverse group of participants that represented the US population and found the calorie counting device performs very well, with only one-third of the error of a smartwatch. During the research, the team was able to understand the basic issue with other wearable calorie counters discovering that error is introduced because they rely on wrist motion or heart rate.
The problem with relying on wrist motion or heart rate is that neither is particularly indicative of energy expenditure. The team found that lake motion is more telling, and experiments confirmed that was correct. Their wearable device requires two small sensors to be worn on the leg along with the battery and a portable microcontroller. The system costs about $100 to make, and the researchers made the list of components and code required for the system freely available.