Sitting slightly forward of centre of the rebounder mat, lean back slightly and lift both feet off the floor. You will feel your hip flexors have switched on.
Start to bring the knees in toward the chest as in a bicycle movement (alternating hip flexion) and at the same time also rotate shoulders towards the opposite knee to get a good torso rotation/twist pattern.
This is a great exercise for toning and strengthening the muscles around the waist.
This one isn’t easy!