#3 Weighted Sit Ups
The weighted sit up is a progressive form of the traditional sit up. This exercise strengthens the entire core region including the lower abdominals, hip flexors, and lower back.
Instructions:
Step 1: Lie on your back and bend your knees at 90 degrees. Make sure that your feet are flat on the floor.
Step 2: Now hold a dumbbell against your chest by hugging it with your arms.
Step 3: Perform a sit up by raising your upper torso and contracting your core. Try to touch the back of your forearms to your thighs.
Step 4: After a brief pause for a second slowly lower yourself back to the starting. This completes one rep.
Important Tips: Do 3 sets of 15-20 reps each. Start with a weight which you are comfortable with. If you have a problem in anchoring your feet then slide your legs under the handle of two very heavy dumbbells.
Next Up: Rolling Planks