Serena Williams‘ 22nd Grand Slam title win at Wimbledon says a lot about her training style as an athlete over the past two decades. In addition, Kevin Hart has gained respect and inspired many with his “Run With Hart” movement, that gets his local fans from every city to run a 5K with Hart himself.

Hart and Serena have joined together and created high intensity workouts for users to incorporate into their exercise routine on the Nike + Training Club app. In the promotional video for the new initiative, the two work on flexibility. Hart hilariously complains he’s not as flexible as he could be because of a never heard of diagnosis called “water hamstring-itis.”

The two make a very competitive yet interesting training collaboration, which will make for an even more interesting workout. The Serena Williams and Kevin Hart workouts are now available on the Nike + Training app for iPhones and Androids.