Truly one of the most effective pieces of work out equipment, the Synergee Core Mat helps athletes trim up their waists by improving on the original ab workout, the sit-up. Designed contoured to your lower back to provide support and to help prevent Injury during rigorous abdominal exercises. Use the Synergee core mat as an alternative to an ab wheel, ab carver and ab roller. No more balancing! Unlike fitness balls and ab wheels the Synergee core mat will not roll or wobble on you so you can concentrate on your core exercises.