One of the trends we're expecting to see more of at CES is wearable technology built directly into clothing — something that comes with its own practical constraints (like washing it) but could ultimately be more useful than a wrist device that ends up in a drawer. Something that you wear all the time anyway. Something like... a bra.

OmSignal, a Canadian company that makes "smart" compression shirts for men, is showing off a sports bra for women that tracks heart rate, breathing rate, and calories burned, among other metrics. The data is recorded through a sensor-filled black box that snaps into the lower band of the sports bra, along the rib cage. The data is then wirelessly shared to OmSignal's mobile app. The mobile app will also have a new option called OmRun, which, when used with the smart bra, will measure distance, pace, breathing rhythm, and fatigue levels during running workouts.

A smart bra that tells you to work out harder

We haven't tested this enough yet to warrant a full review, but I've worn a pre-production OmSignal sports bra during a couple workouts now, and it's actually comfortable — way more comfortable than I expected a sports bra with a thick black plastic box to be. It has optional padding, adjustable straps, and a secure clasp in the back.

Maybe more importantly, the app offers some interesting insights. Not only does it show a live stream of biometrics during exercise, but afterward, it told me which heart rate zones I hit and for how much time, my estimated recovery time, and something called a "push score." (You feel pretty good about an hour-long workout until an app tells you that you exercised at a light warm-up level for around 45 minutes of that workout.)

Not surprisingly, the bra isn't cheap, with a price of $149. OmSignal's compression shirt kits for men start at around $275, and cost even more once you throw a high-end apparel partner (like Ralph Lauren) into the mix. Other companies selling sensor-filled clothes, like Athos and Hexoskin, charge comparable or higher prices for their products, as well.

Stay tuned for a full review of the smart bra, which is expected to ship in the spring.