This Leg-Based Wearable Might Track Calories Better than Smartwatches

Estimating calorie counts is an imperfect science, particularly with regards to monitoring what number of you’ve burned throughout a given exercise. Wrist-based health trackers and smartwatches’ estimates for calorie burn could be off by as much as 40-80%. However, engineers from Stanford declare they’ve created an inexpensive, accurate device that you may truly make for your self. But as an alternative of carrying it in your wrist, you strap it to your leg.

The gadget, which was revealed in Nature Communications, makes use of two “inertial measurement” sensors worn on an individual’s shank and thigh. The elements are run by a microcontroller on the hip and measure how briskly the leg rotates and accelerates whereas in movement. To measure its accuracy, the engineers had check topics put on their gadget together with two smartwatches and a coronary heart price monitor throughout actions equivalent to strolling, operating, biking, climbing stairs, and transitioning from strolling to operating. The outcomes have been then in comparison with calorie burn measurements collected from a laboratory-grade system. Study members have been additionally of various ages and weights.

Long story brief, the leg-based gadget had an error price of 13% throughout frequent actions, in comparison with 42% for smartwatches and 44% for activity-specific smartwatches.

According to Stanford engineers, the issue with wrist-based gadgets is they typically calculate calorie burn primarily based on a mix of wrist motion, trunk motion, and coronary heart price. However, coronary heart price isn’t at all times associated to what number of energy you’re burning. A cup of espresso, for example, could enhance your coronary heart price regardless that you’re not metabolizing at a sooner price. Likewise, workouts like out of doors biking don’t have as a lot wrist or trunk-based movement. Another profit is the gadget is able to delivering knowledge in a sooner, extra accessible method. Currently, laboratory-grade strategies of measuring calorie burn are costly, require a masks, and aren’t precisely transportable.

“A lot of the steps that you take every day happen in short bouts of 20 seconds or less,” Patrick Slade, lead writer of the research and Stanford graduate pupil in mechanical engineering, stated in a press launch. “Being able to capture these brief activities or dynamic changes between activities is really challenging and no other system can currently do that.”

“An issue with traditional smartwatches is they only get information from the movement of your wrist and heart rate,” Mykel Kochenderfer, affiliate professor of aeronautics and astronautics at Stanford and the paper’s co-author, stated in a press release. “The fact that Patrick’s device has a lower error rate makes sense because it detects motion of your legs and most of your energy is being expended by your legs.”

This doesn’t imply that health buffs or anybody trying to shed some pounds will be capable to begin strapping gadgets to their legs, nonetheless. This explicit system is a proof-of-concept gadget. However, a neat factor is the engineers have made the code and component list publicly accessible for anybody who needs to strive making their very own rig for about $100. In a video, Slade famous that in a business setting, the gadget may doubtlessly be much more inexpensive.

The calorie burn downside is one which’s plagued wearables for a very long time. For tech reviewers, there’s no option to check or gauge calorie burn accuracy, even when it’s a metric that many customers wish to know for managing weight. Plus, completely different gadgets use proprietary algorithms that could be primarily based on completely different sensor knowledge. However, it’s necessary to notice that this doesn’t imply smartwatches or health trackers are utterly ineffective for well being monitoring. They can nonetheless present helpful perception into your baselines, in addition to assist observe your progress in numerous sports activities. It’s only a pleasant reminder that you simply shouldn’t put a lot inventory into what number of energy they are saying you’re burning.