The key to a flat, toned stomach is to perform a variety of abdominal exercises. Straight-leg situps work different muscles in your midsection and can tone your lower and upper abs, sides and lower back. Different variations of the straight-leg situp can also work portions of your legs and backside.
Traditional Straight-Leg Situps
When you think of a situp, you probably picture someone lying on her back with knees bent, lifting her upper body to her knees. The straight-leg situp is similar, except that you keep your legs straight out in front of you rather than bent. Begin this exercise by lying flat on the ground with your legs straight. Place your hands behind your head, keeping them loose to prevent pulling on your neck. Pull your upper body all the way up to a sitting position, then slowly lower your upper body back down to the ground. The movement should be a smooth, rolling motion along your spine as you roll up and then back.
The "V" Situp
Start by lying flat on your back with your arms and legs fully extended. Keep your arms and legs straight throughout this motion. Focusing on using your abs to pull yourself up, bring your arms and legs toward each other; touch your hands to your shins if possible. Your body should look like a “V” when you are in the full situp position. Slowly lower yourself down until you are once again flat on your back with your arms and legs extended. This entire movement should be done at a slow pace to ensure proper form and to prevent injury.
Hip raises work your lower abdominals and back in one motion. Start by lying flat on your back, either with your hands by your sides or clasped behind your head. Your upper body should not move at all during this exercise. Keeping your legs straight and together, bring them up as far as you can, perpendicular to the floor. In a small, controlled motion, lift your tailbone off of the ground, focusing on pushing your legs straight up towards the sky as you lift. If you have your hands flat on the ground next to you, you may use them for added leverage. The lifting motion should be straight up with no rocking of the hips or legs.
Straight-leg situps take practice due to their increased level of difficulty. If you have suffered a back or neck injury, you will need more support as you work your abdominals and should avoid straight-leg situps. If you feel you are fit enough to do straight-leg situps, always use a mat or cushioned surface under your back and maintain full control over the motion to ensure proper form. Consult your doctor if you have any concerns about straight-leg situps prior to attempting them.