The lines you see below have been unearthed by poking around some Google code, and they reference a mysterious fitness API, that will allow "fitness data from sensors on your Android device" to be collected.
Now what will get this data, and how will it be used, remains a mystery, but we've heard about a Google smart watch in the pipeline, which doesn't preclude other wearables to be in the cards, too, given that we already have the sophisticated Glass headwear offered by the folks in Mountain View. Google was just leaked to be working on contact lenses for diabetics, which can grab glucose levels from tears alone, so we can only imagine what it can do to fitness tracking apps and gizmos if it sets its mind to it.
The fitness API can also be used by dedicated applications, returning charts and graphs on the state of your vitals, calories burned, distances covered, and so on. In short, there might be a whole framework prepped out for release, that would revolve around Android and wearables, to counter the rumored functions of Apple's iWatch, which is also said to include fitness tracking sensors and the like.