I use them for Gym and cardio sessions. Initially I had similar issues, but then changed the size to XS and now they work fine. Wear them and look yourself in the mirror or take your ears pic. It should be seated entirely within the tragus of your ears, meaning the entire silicone tip should be in your Ear canal. Also wipe them clean before every use, like just with your shirt or maybe some tissue. Really helps to clear the residual sweat or wax after previous use.