Runkeeper, one of the most popular new apps for tracking exercise data, this morning launched its ambitious Health Graph API wide open to the public. The platform for integrating apps and hardware with the fitness data tracking service had been tested in private alpha for several months by a select handful of partners. It’s now available to anyone who wants to build apps to analyze, visualize or take action based on data from Runkeeper, or to publish data to the platform. Making health and exercise data programmatically available has benefits not just for the individual but possibly for society as a whole as well.

Runkeeper decided in January to stop charging for its popular iPhone app and focus on being a platform play. Independent exercise motivation service Earndit has called integrating with the Health Graph API one of the best decisions that company has made yet: “Not only did we get a flood of new users from the integration, but it also validated our product in the marketplace.??”

Runkeeper CEO articulated his long-term vision for the API in an email this morning:

Whoever steps up to tie together the world’s health info needs to be able to do so in an independent/open way, meaning it will not be a brand or device manufacturer. They will also need to get massive scale on the consumer side first before being able to tie everything else (gyms, races, doctors, games, rewards platforms, fundraising platforms, wellness platforms, etc.) into the platform in a compelling way. Massive consumer adoption is the ‘ticket of admission’. And if they stay intentionally ‘thin and horizontal’, like we plan to do, BIG companies can get built in each of these vertical categories over time, and we become simply the thin layer that is the glue that ties everything together.

“From there, the entire healthcare industry can be reshaped. As a user, you should be able to authorize anyone you choose to access your health info (the doctor, your personal trainer, your running coach, etc.), and the things you do while you are there should tie back to the Health Graph. Over time, as the platform gets more and more scale, this system will be able to leverage the massive aggregate dataset to ‘self optimize’, making the world healthier and healthier in the same way that Amazon provides it’s users a better personal shopping experience.

That aggregate dataset could be of use in helping offer much more informed health advice and care for individuals but also in building more informed evaluation of groups. “The power of social tracking far surpasses individual tracking,” wrote Health 2.0 advocate and medical commercial strategist Chris Hogg last Fall.

“With a well defined and relevant peer group, I think the value of tracked data will grow exponentially. In addition to seeing how you are trending relative to your peer group, the Graph makes it possible to compare two groups who are essentially equivalent, but differ on one key characteristic: drug A vs. drug B, migraine with aura vs. without aura, frequent exercise vs. infrequent, etc. With enough data on each user, over time these could become well matched and well controlled studies.”

Hogg says he thinks a universal Health API is a long shot, but is also that “it is the way things should be, so I hope it will happen someday.”

Time will tell if Runkeeper can lead the mobile app charge into a new future of health where data isn’t siloed but is tracked through devices and flows freely between authorized apps competing to out innovate each other and best serve consumers.