The Side Plank with Leg Raise is a great step up from a simple side plank. Just like the side plank, this exercise will work your obliques, however the addition of the leg raise will also target the hip abductors and glutes.
This exercise involves getting into your side plank position before raising your top leg up and away from your lower leg, holding the position at the top of the movement and then lowering the leg back down in control.
Try to keep your upper body and hips still throughout the movement and continue looking straight ahead.
We can also do this exercise using a band:
With a band this exercise is performed in the exact same way, but with the addition of a band around the shins. This is a significant step up from performing the movement without a band and should only be done once you have mastered the technique of the more basic movement.