Under Armour launches Armour39 performance tracking system, we go hands-on

Under Armour has always touted the scientific underpinnings of its sports apparel. From moisture wicking to heat trapping and everything in between, the company is quick to assert that it isn't just another athletic clothing company. But, performance enhancing shirts and pants have their limitations and, arguably, performance monitoring is a far more interesting and burgeoning field. In 2011 it dabbled with E39, a compression shirt with a space to insert a "bug" that included and accelerometer and heart rate monitor. Today, at an event in beautiful, chilly New York City, it officially unveiled the next evolution of that toe-dipping, Armour39. While there may be a shirt in the future, for now the system consists of a traditional chest strap, an iPhone app and an optional watch for those that don't like to carry their expensive smartphone with them on runs.

The only essential piece of equipment is the module itself and the strap. The new bug is quite a bit smaller than the original, which means you won't be able to pop it into an E39 shirt if you happen to have one. Inside the tiny, light monitor is a dedicated CPU, an accelerometer, storage and a Bluetooth 4.0 radio. Along one edge are a pair of metal probes that connect to receptacles in the strap that feed it data from the heart rate sensors. It clips in with a satisfying click and requires a decent amount of force to remove. Not so much that it's annoying, but enough that you feel confident it won't fall out while you're sprinting around the track. The strap itself feels stunningly soft and comfortable. Having worn a few different fitness monitoring solutions in my day, this seemingly small detail lent the whole package a seriously premium feel. Plus, who wants to deal with chaffing or lost chest hair while trying work their guns? The bug operates on a standard watch-style battery, which the company claims should last for up to a year.

The Armour39 app, which is iOS only for the moment, gives you a quick way to monitor information like heart rate, calories burned and intensity. The latter, which sounds pretty abstract, is determined by things like your maximum heart rate and other metrics that you can enter into the app, making it a performance measurement specific to you. Lastly, there's WILLpower, an holistic score of how hard you're pushing yourself on a scale of 1-10. The app uses a proprietary algorithm that takes into account not only your heart rate and position, but also past performances to determine your level of effort.

The last piece of the puzzle is the watch, which we were a little disappointed to find out didn't include GPS for proper run tracking. Instead it just gives athletes a way to keep tabs on all the data generated by the bug without having to take their delicate iPhone with them to the gym. While runners would probably enjoy the addition of location monitoring, its absence does mean you can expect up to a year of use on a standard watch battery. The Armour39 system will hit shelves on March 20th, with the module and strap bundle costing $150 and the watch $199.

Edgar Alvarez contributed to this report.