Lie flat on an exercise mat on the floor, with your thighs vertical but knees slightly bent. Extend your legs fully and place your hands’ palms down, flat on the floor beside you. Keeping your feet together and squeezing your abs, raise your tailbone off the ground and move your feet up. Be careful not to use momentum. Hold for a count of one and return by slightly letting it touch your butt to the ground with control and repeat. Do as many as you can for 40 seconds with good form.
Image Credits: Reverse Crunches