The "abs" consist of the rectus abdominis, transverse abdominis, and inner and outer obliques. The rectus abdominis is the large muscle centered between the chest and pelvis, and the obliques run down the sides of the stomach in a diagonal direction. With ab workouts, your goal is to target as much of this muscle fiber as possible for full development. The captain's chair leg raise is a good exercise for obtaining this achievement.
Benefits of Exercise
The captain's chair looks like a large chair with no seat. It has a padded backrest, padded horizontal supports for the arms and supports for your feet. Regular ab exercises on the floor or with other machines tend to single out one segment of the abs. The captain's chair leg raise surpasses this goal. According to the American Council on Exercise, the captain's chair exercise ranks second highest of all ab exercises for rectus abdominis activity and in first place for oblique recruitment.
A standard leg raise is performed from a hanging position on a pullup bar or a face-up position on the floor. While both of these exercises are beneficial, the captain's leg raise trumps them both, because as soon as you get into position, your abs have to contract to keep your upper body still. As an added benefit that the pullup bar does not offer, your back is completely supported throughout. To gain the benefits that the leg raise offers, it is important to use proper form.
Begin with your back pressed against the back rest, feet on the lower supports and forearms resting on the upper supports with your hands gripping the handles. Slowly remove each foot from the supports and let your legs hang straight down. Keeping your legs straight and together, lift them in the air in front of your body. Once your legs are parallel to the floor, slowly lower them down and repeat.
Other Muscles Targeted
The motion involved with pulling your thighs closer to your stomach is called hip flexion. Whenever you flex your hips, you work the quadriceps and the hip flexors. The hip flexors run from the lower stomach to the top of the thighs; they consist of the iliacus and psoas major, also known as the iliopsoas.
The standard leg raise might be too challenging if you are new to exercise or have not worked out in awhile. To do an easier variation, bend your knees as you raise your legs in the air. You also have the option of lifting your legs or knees to your sides as you raise them. This will shift more of the focus to your obliques.
The captain's chair is a bodyweight-oriented machine. This does not mean you cannot add resistance with your workouts. You just have to get creative. Either strap ankle weights to your lower legs or pinch a dumbbell or medicine ball between your shins when you do exercises. Ankle weights generally range from five to 10 lbs., and you can adjust the resistance in 1/2-lb. increments by sliding small weights into compartments. Once you are able to do 20-plus reps with any captain's chair exercise, it is a good indicator that you need more resistance.