“Shipping fees will be waived prior to your order confirmation by our CS team”Wonder Core works your abs twice as hard. Sit-ups and crunches only work your muscles on the way up; Wonder Core reclines, working your core all the way up and all the way down to double the resistance. With 180° of motion, you can isolate and train you lower, middle and upper abs for a toner, tighter core. The recline stretches muscles, helping to relieve back pain. And you can also perform knees tucks and twisting oblique exercises on the swivel seat. The Wonder Core lets you take advantage of resistance on the way down and up with every repetition so you're essentially getting double the workout in half the time! This brilliant fitness tool also provides a full 180 degree range of motion, meaning you can isolate and train your lower, middle and upper abs-more more for tighter and faster results. A thick foam cushion supports create an invigorating massage up and down your back as you train to help revitalize your spine and back. And best of all, you're nestled in an ultra-comfortable seated position with your head and neck fully supported through the full range of motion so anybody can do it!