A curl-up with a twist is made more difficult during the lowering phase by:

The curl-up with a twist is a core-strengthening exercise that targets not only the abdominal muscles but also involves rotation, which adds complexity to the movement. During the lowering phase of this exercise, several factors can increase the difficulty level.

Moving the hands from across the chest to cupping the ears significantly changes the way the body is supported and balanced. When the hands are placed behind the ears, more weight is shifted further away from the center of gravity, increasing the load on the core muscles required for stabilization and control during the movement.

Changing the lever difficulty also plays a crucial role in increasing the challenge during this phase. If the legs are kept straight or elevated while lowering, the leverage increases as the distance from the pivot point (the hips) to the end of the lever (the feet) becomes greater. This means more force is needed from the abdominal muscles to control the descent.

Additionally, the laws of gravity act continuously during the lowering phase. Gravity introduces constant downward force that the core must work against, and the further the body moves away from a stable position, the more challenging it becomes to maintain control.

All these factors contribute collectively to make the curl-up with a twist more difficult during the lowering phase, enhancing the effectiveness of the exercise in