What is a suggested way to make the Twist exercise more challenging?

Keeping the knees straight during the lifting and lowering phases of the Twist exercise increases the challenge by engaging more muscles, particularly in the core and lower body. When the knees are straight, it requires greater stability and strength in the abdominal muscles to control the movement. This straight-leg position demands that the body actively stabilizes itself throughout the twist, intensifying the effort needed to perform the exercise correctly.

By contrast, with the knees bent, the engagement of the core muscles is somewhat reduced because the legs can assist in maintaining balance and stability. Lifting the body without lowering it or increasing speed can also change the dynamics of the exercise, but they do not necessarily add the same level of challenge to the specific muscle engagement associated with maintaining straight legs. Therefore, the straight knee position is the most effective modification for increasing difficulty while ensuring proper alignment and control.