1.Bent-Knee Leg Raises:
Hold onto a chinning bar with an overhand grip. Hang at arms' length. Bend your knees and then lift your legs as high as possible. Hold them at the top of the movement for a two-count and then lower back to the starting position. For variety, twist at the top of the movement. This variation works the lower "abs" but also brings the intercostals and serratus into play. Alternate side to side. Avoid swinging and allowing the legs to come apart.
Lie on the floor with your feet on a bench and your legs bent at a 90 degree angle. Place your hands at your temples. Raise your head and shoulders toward your knees with a sit up motion and simultaneously lift the pelvis. Feel the lower and upper "abs" contract together. Flex the abs hard at the top of the movement to get maximum contraction. Avoid pulling on your head with your hands. It may help to exhale just before "crunching" upwards.
3.Leg Tucks On The Floor:
Lie on your back with your hands at your temples. Lift your upper body as if doing a sit-up. Simultaneously, bring your knees up as far as possible towards your chest. Try to touch elbows to knees. Lower your back to the starting position. For best results, perform this exercise in one slow and controlled motion.
4.Seated Leg Tucks:
Sit sideways on a bench and grasp the edges of the bench for support. With bent knees, raise your legs slightly and then straighten them. Lean backward as balance requires. Next, lift your knees up towards your chest while keeping your lower legs pointed downward and flexing (tightening) your "abs" as hard as you can. Keep continuous tension on the "abs" throughout this movement. This works both upper and lower abdominal muscles.
5.Vertical Bench Leg Raises:
Position yourself on a vertical bench. While using your arms to hold your body steady against the bench and keeping your legs straight, lift your legs up as high as possible. Hold your legs up at the top of the movement for 2 seconds and then slowly lower them down. Keep your back pressed against the bench at all times.