An effective core exercise.
Näin teet sen
Sit with your knees bent, feet flat on the floor. Grasp your legs under your thighs, slightly above your knees.
Lean back slightly. Lift your feet off the floor so that your shins are parallel to the floor.
Extend your arms straight out in front of you at shoulder height, with palms facing up.
Keep your knees bent for 30 seconds. Take this time to really engage your deep abdominal muscles and lengthen your spine, keeping your chest open.
Place your feet back on the ground and relax for a few breaths.