Tough AB Exercises

To decide which abdominal exercises are considered tough, look at the commissioned study done by the American Council on Exercise. They placed electrodes over the key abdominal muscles and performed multiple types of abdominal exercises. The exercises that provided the most muscle activity were the captain's chair exercise, bicycle maneuver and stability ball crunch.

Captain's Chair Knee Lifts

The captain's chair is an apparatus with a cushioned back, forearm pads and handles that stick straight up. Mount the captain's chair. Hold your body weight on your forearms by depressing your shoulder girdle down and through your arms. Allow your legs to hang straight without your feet touching. Inhale through your nose. Exhale and tuck your knees up toward your belly button. Inhale and resist gravity as you slowly lower your legs. Exhale, tighten your abdomen and raise your knees again. Continue until you experience abdominal muscle failure. Perform three sets.

Criss-cross

The criss-cross is also called the bicycle maneuver. It challenges all three of your abdominal muscles, and also the lower and upper muscle fibers. Lie on your back with your hands behind your head. Bend your knees up and look down your body. Inhale, straighten one leg straight out and bring your opposite shoulder across and toward your bent knee. Exhale and reverse the motion. Continue to alternate this criss-cross motion. Keep your abdomen compressed downward throughout the exercise to activate your deepest stomach muscle, the transverse abdominis. Perform three sets to muscle failure.

Hanging Knee Raises

The hanging knee raise challenges your entire abdomen, especially your lower abdominal muscle fibers. Hang from a chinup bar without your feet touching the floor. Inhale to prepare for exertion. Exhale and raise both knees up toward your belly button or up to your chest. Continue until you experience abdominal muscle failure. Then raise your knees up side-to-side. This will work your side abdominal muscles --- the external and internal obliques. Always lower your legs with control.

Stability-ball Crunch

The stability-ball crunch helps you compress or flatten your abdomen while providing strenuous abdominal work. Lie with your mid-back and shoulder blades on top of the stability ball. Place your feet apart and flat on the floor. Tighten your buttocks and raise your trunk to a comfortable position. Place your arms across your chest. Inhale and open around the ball. Exhale, compress your abdomen into your spine and raise your torso. Continue for 10 repetitions. Immediately change your arm position by placing your hands behind your head with your elbows open. Continue to raise and lower your torso for 10 more repetitions. Change your arm position again by reaching your hands straight up by your ears toward the ceiling. Continue to raise and lower your torso for 10 repetitions. Repeat this sequence until you experience abdominal muscle failure.