One of the biggest problems with today's wearables is implementation. In their current form, they're basically accessories you need to take off and put on to charge and sync. For both general purpose and fitness-focused trackers alike, you need to strap something onto your wrist, or snap a heart rate monitor onto your chest for detailed biological stats. This extra piece of hardware can be easy to forget if you already own one, and a barrier to entry if you don't.

A startup called OMsignal wants to make wearable tech as natural and unobtrusive as the shirt you slip over your head each day. The company has developed a line of workout shirts that, thanks to some specially woven threads, are able to measure health stats like your heart rate, breathing rate, and calories burned.

"We need something that complements life, without getting in the way of life," OMsignal CEO Stéphane Marceau says of the current state of fitness trackers. Clothing was, naturally, the most friction-less fit. "Clothing is the only type of wearable you've been wearing your whole life. Clothing also allows us to access biological functions where they actually happen."

OMsignal's fitness tracking hardware is in this little black box. Image: OMsignal

Of course, we aren't quite to the point of having sensors and microprocessors directly built into clothing. OMsignal's shirts, which have the style and texture of a high-quality, form-fitting workout shirt, feature a band around the chest woven with conductive silver-based thread. This band can transfer electrical signals to a piece of hardware OMsignal calls a "little black box" that snaps onto the shirt. The box connects to your handset via Bluetooth and houses an accelerometer, gyrometer, and magnetometer for tracking your movements in space. Because that band wraps fully around your chest, the device can also track your heart rate and the way your chest expands and contracts as you breathe. This lets OMsignal measure additional stats that are impossible for other wearables–estimates of things like your stress level (derived from heart rate variability) and breathing regularity (are you taking frequent, shallow breaths or slow deep ones?).

Because data is being captured at your chest, it should be more accurate–or at least less noisy–than data gathered from a wrist or some other part of the body.

Like other fitness trackers, OMsignal has its own app that translates this data into potentially meaningful, actionable information. It provides immediate feedback about your fitness and stress levels in the form of different app screens and charts. It can also act as a guide during training sessions. Say you're at the gym, in the middle of some reps and working hard. The app can tell you exactly how much exertion you're putting your body under, and can tell you if you're in the zone for losing weight, or increasing your aerobic capacity. It can also instruct you to slow down and deepen your breathing if your goal is to increase fitness. Using the biological signals the shirt measures, it can even tell you how much energy you have left at the end of the day, which is useful for planning the next day's workout. We'll have more details about how the app works, and how well it works, once we get a chance to use it firsthand.

OMsignal's initial collection includes four moisture-wicking, anti-microbial men's shirts: an undershirt, a sleeveless shirt, a casual T-shirt and a long-sleeved shirt, in six different colors. A ladies' collection is in the works too. When asked about durability, Marceau said they hadn't had any problems thus far in their 9 months of trials–he recommends not putting the shirts in the drier though.

You can grab a shirt and a little black box for $200 during the month of May (after which the price goes up to $240), and purchase additional shirts for $100 to $140. OMsignal's products will ship this summer.