The decline sit-up twist is a bodyweight core exercise that targets the obliques, as well as the rectus abdominis or "six pack" muscles. Sit-up variations are usually performed for moderate to high reps, such as 10-15 reps per set or more, as part of the core-focused portion of a workout.
Develops strength in multiple abdominal muscles, as well as the hip flexors
Simple way to progress decline sit-ups when they become too easy
Can be progressed by increasing the decline angle over time or adding weight