V-sit crunches:
Sit on the edge of the bench with your arms by your sides. Raise your legs as high as you can, keeping them straight and together, and lift your torso up towards your thighs so you form a V-shape. Keep your back straight and try to keep your movements smooth and controlled – avoid jerking. You can keep your hands on the floor or bring them up to meet your feet. Then slowly lower back to the ground.
Mistakes and Recommendations:
Do not use inertia; keep your position stable; slowly stretch your legs and quickly raise them; as you progress, use additional aggravation, such as a dumbbell between the feet.
Breathing pattern: exhale when you raise your legs and inhale when returning to the original position.

V-sit crunches.