The HIT Fitness Ab Mat is essentially a covered foam mat with a slope/arch. The ab mat has been ... designed to perfectly support your lower back when performing sit ups. The ab mat ensures that your spine is kept in a neutral position throughout the entire movement which allows your abdominal muscles to move through a full range of motion safely. This ensures that the abs extend and contract fully throughout the movement. The HIT Fitness ab mat is an extremely light and portable piece of gym equipment which makes it ideal for home and commercial gym workouts.