Lie on your back with your legs bent and feet flat on the floor (approximately hip-width apart), knees bent at about 90°, hands clasped in front of your chest, and the lower back in a neutral position (with light contact with the floor). Tighten your abdominal muscles, lift your shoulder blades slightly off the floor (the lower back remains on the floor), hold the position briefly, then slowly lower your upper body again. Breathing: Exhale as you lift up, inhale as you lower down.
Attention:
Keep your lower back on the floor at all times, lift your shoulders in a controlled manner, actively engage your core, avoid jerky movements, do not lift your feet (the hip flexors should do most of the work), and do not push your neck forwards (keep your head in line with your spine, not tilted forwards towards your sternum).
Lighten:
Extend your arms out in front of your chest at an angle; reduce the range of motion and lift your shoulders only slightly off the floor.
Harden:
Place your hands lightly on the back of your head (do not pull on your neck) or even hold them above your head; add extra weight (hold a dumbbell or medicine ball against your chest); Extend legs straight out instead of bending them (greater leverage means greater tension); Exercise variation: Extend legs upwards (V-up) on an incline board (lift upper body against gravity for greater intensity).
Variation:
Adjust the distance between your feet and your bottom.
