LAS VEGAS — A number of smart shoes made their debut at CES 2016, but all have the same limitation: Once the shoe wears out, or you want to wear a different shoe, you can't remove the tracking sensors.
Mettis Trainer solves that problem by putting all of its sensors into a removable insole. I checked out these slip-in, slip-out trackers ($199 on pre-order), which will be available in the second quarter of 2016.
Inside each insole is a thin strip with three flexible potentiometers, or what Mettis calls BendSensor (pictured above, resting on top of an insole). There are two potentiometers near the front of the foot, and one near the heel. Each is a few inches long, and can detect anywhere along its length where pressure is being applied. With these, the insoles can detect how you're shifting your weight and what you're doing, be it golfing, running or anything that involves wearing shoes.
The insoles weigh less than 60 grams, and are thin enough so that you shouldn't notice them in your shoe. That's where the real benefit of this device lies: If you play more than one sport, you can still gather pertinent data about how you're placing your feet without needing to purchase another pair of teched-out shoes.
Although it can potentially be used for a variety of sports, Mettis is first developing an app for golfers. Golfers should be able to see how they shift their weight from one foot to the other while taking a swing, and the app will deliver feedback in real-time. Mettis is also releasing an API for its insoles so that its data can be used with other fitness apps.
The rechargeable batteries in each insole are good for 12 hours of use; they'll get back to full power in about 4 hours using a wireless charger.
The Mettis insoles are intriguing not just for their technology, but for their versatility. If you want to improve your performance across multiple sports and activities, the Mettis trainers could be it. But to be truly useful, the data it collects will have to be accessible to other fitness apps, and I'm waiting to see which partnerships Mettis makes first.