The forces of gymnastics movements on bars and rings cause the grips to pull against the bottom sides of the palm. This can be uncomfortable especially with leather grips. This is the reason why it is a standard practice amongst competitive gymnasts to wear wristbands underneath their grips. The wristbands not only make the grips more comfortable, they also help with sweat which reduces slipping and preserves the integrity of the leather. You can find wristbands at victorygrips.com.