Plank knee twist
Primary muscles: Abs, glutes, hamstrings.
Adjust your speed based on your ability in order to maintain good form throughout the exercise. Ensure that you do not raise your bottom – your body should stay aligned flat in the plank.
2. Twist your lower body to the right, swinging your right knee under your abs to complete the twist toward your left elbow.
3. Twist back to center, replacing your left foot next to your right. Then repeat with the right side of the body.