Microsoft knows it's almost bikini season so they're getting ready to release Kinect Play Fit which will let all Xbox gamers track their exercise progress across most Kinect games via the cloud. Play Fit will be accompanied by a hardware accessory, currently codenamed Joule.
What Joule will allow gamers to do is, "track their heart rate wirelessly and ensure any exercise is within a target goal for weight loss, strength, or cross-fitness workouts," according to article in The Verge. You won't need Joule to make use of Kinect Fit Play, it's just an extra accessory for those who really want to track their progress.
Microsoft hasn't announced a release date for the Kinect Fit Play or Joule yet, but we'll probably hear more as E3 gets closer. As we get more details we'll be sure to give you an update.
Source: The Verge