Taking the basic clam and doing it in a side plank makes the butt work overtime to help support the plank.
- Lie on your left side with knees slightly bent and your elbow underneath your shoulder.
- Press into your bottom forearm to lift the hips as high as possible, keeping your abs engaged.
- Raise your top knee to open the thighs like butterfly wings, then slowly lower the knee, completing one rep. The move is similar to the clam.
- Complete 10 reps on each side.