One of the most effective exercises for this area is the reverse crunch with ... Lift your legs together, keeping them straight, until they form a 90-degree angle with the floor.

Although crunches seem easy ... Bend the left knee and straighten the right leg at a 45-degree angle, while also crunching your right elbow toward your left knee. Return to start, then bend ...

The exercise is a variation of an ab crunch, where one leg flexes while the other extends ... your thighs at right angles to the floor and your calves parallel to it. ‘Cycle’ your legs ...