This exercise is seen in both body conditioning and Pilates classes. It is a great exercise to target the external obliques and rectus abdominis.
Lie on your back with your knees in a tabletop position and your hands behind your head.
Keep your tongue pressed against the roof of your mouth and exhale, drawing your navel to your spine as you lift your upper body away from the floor. Keep your elbows pointing out, away from each other.
Extend your right leg and, keeping your elbows wide, rotate your torso to the left, bringing your right elbow toward your left knee. Perform this action without pulling on your neck. Point your left elbow toward the wall behind your head.
Switch legs, and bring your torso back to center.
Repeat the twist to the other side.
The bicycle crunch is about toning your abdominal muscles. These muscles are voluntary muscles, and you must intentionally move them. Do not pull with your arms, but rather initiate each action from your upper abdominal and oblique muscles while stabilizing your hips by using your lower abdominal muscles. Maintain a wide chest as you perform this exercise.
Repeat this 6 to 10 times on each side.
Make sure to maintain a neutral spine while performing this exercise. If you tuck, arch, or rock, it is incorrect.
Lift your extended leg higher to make this exercise easier. You must be able to maintain a neutral spine as you work. If your navel pops out or your back arches, lift your leg higher and correct yourself.
You can also try keeping one foot on the floor as your rotate toward the other knee that is off the floor. Each time you switch, rather than extending one leg, bend your knee and place your foot on the floor.