Lay on your back, with your hands anchored behind your head, head neutral. Start with your hips flex & leg straight, pointed to the sky.
Engage your lats & core by actively pulling with your arms, pressing the lower back into the floor & driving the elbows forwards.
Lower one leg with control, while keeping tension on your core & not allowing your lower back to lose contact with the floor.
Keep the other leg static, flexing your quads and pointing your toes to behind you.
Return to the start & switch sides. Repeat for repetitions.