If you work up a sweat, they fall right off. So NO exercise. Mack/ is right, I would sometimes find out that I had TWO of them on when lighting up. HOWEVER, the really good news is that I realized I had quit smoking when I realized, on a couple of occassions, that the darned things had fallen off ten or twelve hours before I felt the urge for a cigarette, and I hadn't even known they were gone.