Did you try comply memory foam tips and over the ear behind the head style? They don't move with that way of running them. Not the comply tips that come in the package either. The stickier ones you order from comply directly.Unfortunately for me, X2's just wouldn't stay in my ear. I tried a number of different wireless earphones before settling on Powerbeats2 which fit PERFECT...too bad the product quality was terrible in the end. I currently rely on the Apple earbuds that come stock with all iPhones for my runs and lifting sessions, and they are more secure than anything I have ever worn, with the only downside being the cords getting in the way. That's why I am hoping the AirPods fit the same. Not sure about their sweat resistance though. Time will tell.
I had the bluebudx for over a year, the x2's for a year and a half i think and now the jaybird freedoms. Ive loved all of them. Never had an issue with coming out of my ears but I've always ran mine the way i described.
The problem with these beats i see is the cable dangles around your neck. I imagine at the gym and sweat you it would be uncomfortable moving your head from side to side and imaging pulling. Its one reason i didn't run the jaybirds that way because they wouldn't slide on the back of your neck smoothy. On the back of your hair over ear you don't feel any of that pulling going on.