PRsue Fitness App by Zone2 Training


Perigee Labs was approached by the athletic training startup Zone2 to collaborate on the creation of a revolutionary running platform, PRsue, leveraging elite training methods proven to achieve personal records. Typically, elite athletes have one or more coaches managing their progress.  The goal for PRsue was to create advanced, science-driven training tools to make PRsue the next best thing to a personal coach for running enthusiasts of all abilities.  The PRsue app empowers individuals to create, execute, and manage a training plan so they can set their next personal record.

The challenge was to implement the patented, complex training algorithms on Apple’s iPhone platforms to create a sophisticated yet highly flexible training plan on top of the standard features of a typical running app.  The app had to allow for custom plan creations based on these algorithms, yet adapt to changes in an individual runner’s performance and scheduling.  As with any running app it had to integrate near real-time location services, bluetooth heart monitors and provide for situational coaching commands.



Perigee engineers worked closely with Zone 2 staff to refine the training algorithms and create the specifications for the multifaceted training adjustment tools that would be needed to provide true flexibility to the runner.

The team built a prototype iOS app to test and validate the numerous complexities within the training algorithms and constructed the prototype server environment and API that would support running data captured from the app users.


Perigee Labs conceptualized, prototyped and refined the app design to provide the optimum User Experience (UX) and access to statistical information at varying levels. The team focused on keeping basic functionality simple while still allowing the power user the ability to dig into advanced performance metrics.

Once the UX and conceptual architecture were finalized, Perigee Labs create a professional and appealing visual design that emphasized functionality and ease-of-use.


To ensure future flexibility, it was decided that the Minimal Viable Product should be introduced on Apple’s most advanced phones, iPhone 7 and 7+, be built with the latest Swift 3 language and run on  Apple’s iOS 10+ – an interesting challenge for our team as these target devices and iOS were still under development at the start of the project. With this design goal defined at the project start, the development efforts were successful in creating a UX that worked equally well on the brand new and legacy devices.

Product Development

Perigee engineers constructed, tested and fielded the Beta app in record time to over 150 users across country using Apple’s Test Flight environment.  This process was invaluable in capturing actual runner feedback of PRsue, it’s UX and suggested improvements, allowing Perigee to refine the server API and search tools, and add server performance enhancements needed to support production.

In parallel with Apple’s pending release of the new phone platforms and beta version of the next iOS, Perigee Labs refactored the product software from Swift 2 to Swift 3 and accommodated the iOS framework and API changes on the most reengineered version of iOS to date.


PRsue was introduced to the App Store two weeks after the iPhone 7 and 7+ became available.  It supports iOS 9 and 10+ and it’s adaptive design supports all iPhone 5’s and above.  The staff at Zone 2 stated “Perigee Labs software engineers are truly elite level, we’re simply amazed how well they hit the mark”.  But the real proof and job satisfaction comes from actual users and how they feel about the final product:

“This is an incredible tool for runners who really want to learn how to run healthy, wise and improve their time. The difference with PRsue compared to other fitness apps is that it does not just track your workouts, it explains and helps you understand how to improve your running. By the end of your first Campaign you will be running stronger and smarter, not harder. The app is really personalized to your fitness level and has all the data you need without making it complicated. I would recommend it to anyone.

– Sun Valley,  ID

“I’ve been running for a few years and using apps the whole time. None of those apps were actually helpful in systematically helping me improve my times. PRsue is the first running app that has made me feel confident about the prospects of breaking through the PR plateau I’ve been stuck in for the past year. The app’s slick interface appeals to the cool-kid in me while the science of it appeals to my inner nerd. Win-win!”

– Washington, DC

“I just completed a training run, with voice overs, and am IN LOVE!  I loved seeing all the stats. I loved the voice over telling me my heart rate, miles covered, and zone changes. It was so fun!”

– Boston, MA

With some truly groundbreaking advances planned for future iterations of the PRsue app, look for Perigee Labs to solidify their position as leaders in the venture technologist and commercial iOS / application development space for the Washington DC region.