Abdominal crunch from 45 degrees supine - legs bent ("Sit up" Core/abdominal strengthening, legs bent, reclined 45°)

Lie down on the bench with the torso section positioned at 45 degrees.
Bend your legs, placing your feet on the bench.
Ensure your knees and feet remain hip-distance apart.
Cross your arms over your chest, then tense your abdominal muscles.
Curl your body forwards away from the support of the bench.
Once you reach the upright position, control the movement as you lower your torso back down to the bench.
Repeat.