Microsoft is preparing to update its Xbox 360 dashboard software to include a cross-application exercise tracking system, according to our sources. Kinect Play Fit will allow Xbox gamers to track their exercise across most Kinect games, providing tracking metrics in the cloud. The software maker is also planning to release a hardware accessory, codenamed Joule, to accompany the Kinect Play Fit service.

The Joule heart-rate monitor will let Kinect owners track their heart rate wirelessly and ensure any exercise is within a target goal for weight loss, strength, or cross-fitness workouts. Although EA currently ships its own heart rate monitor with EA Sports Active 2 for the Xbox 360, Microsoft's Joule monitor will be compatible with most Kinect games — but you won't need it to make use of the new exercise tracking feature of Kinect Fit Play. We don't have a solid release date for the Kinect Play Fit system, but sources familiar with Microsoft's plans have indicated to us that a future dashboard update will introduce the system. We expect the company to detail some of its Kinect plans at E3 next month, alongside more Xbox Live content deals and additional software enhancements for the Xbox 360.

We have reached out to Microsoft for a comment on Kinect Play Fit, and we'll update you accordingly.