Thanks to a coming update to the Microsoft Health mobile app, Microsoft Band users will be able to compete with their friends on Facebook using new social challenges and leaderboards.

The catch? Everyone needs to be using a Microsoft Band. So this is going to be a bit like the “squirt” feature from Zune where it’s a cool idea limited by the fact that few people are actually using the device.

(Technically, you don’t need a Band for this to work. But your friends will need to be tracking steps and calories with the Microsoft Health app, which can work with the movement sensors in an iPhone, Android phone or Windows Phone as well.)

In any event.

“Microsoft Band and Health’s new Social Challenges and Leaderboards help you get motivated, have fun, share your accomplishments and even take each other on in head to head fitness challenges – all in the name of health,” the Microsoft Devices team announced today.

To use this feature, you’ll need a coming version of the Microsoft Health app, so I can only go by Microsoft’s description. It appears that you will be able to connect your Facebook account to Microsoft Health and then see which of your Facebook friends have connected their accounts as well.

“With Social Challenges and Leaderboards, create challenges for steps, calories burned, longest run or bike ride between you and your Facebook friends who also have a Microsoft Band,” Microsoft explains. “Challenges can be one, three, five or seven days.” You will also be able to check your friends’ daily activity on the Microsoft Health Leaderboard (but it’s not clear if that is in the app or web-only).

“Social Challenges and Leaderboards is more than a cool new feature – we know exercising with friends has tangible benefits to improving fitness outcomes,” Microsoft continues. “We hope the friendly competition will keep you motivated and decrease the chances of hitting that snooze button or missing a workout … When you’re particularly proud of an awesome workout or a great night’s sleep, remember that you can share your run, bike, or sleep summaries on social media. Friends can review your data in the public dashboard if you choose.”

What I’d really like to see is Xbox Live achievement integration so you can get achievements for meeting goals. This would be motivational too and wouldn’t require you to know other Band users.

Microsoft Band Users Will Be Able to Compete With Facebook Friends