Complex sentence: Powerlifting belts are of a fixed width, and stiffer than traditional weight lifting belts, since powerlifters generally don't perform olympic style excercises such as the snatch and clean and jerk.
Split into simpler sentences: Powerlifting belts are of a fixed width, and stiffer than traditional weight lifting belts. Since powerlifters generally don't perform olympic style excercises such as the snatch and clean and jerk.