How to Exercise the Abs While Sitting

Seated abdominal exercises do more than strengthen your core. They offer workout variations if you have back problems, are beyond three months pregnant or are unable to exercise while lying flat on your back. Seated exercises also provide a discreet way to tone your abs while driving, working or watching TV.

At Work

If you are seated with limited room to move, such as in your office chair or airplane seat, strengthen your core with simple exercises that use little or no movement. The abdominal hollowing exercise targets your transverse abdominis, the deepest layer of abdominal muscle tissue, with very little movement. Sit upright and exhale as you flatten your abdomen by pulling your navel toward your spine. Breathe normally as you maintain the contraction for 10 to 60 seconds and then release. A seated side bend targets your obliques but requires more movement than the abdominal hollowing. Sit upright with your arms at your sides. Bend to the right as you reduce the space between the right side of your rib cage and your right hip. Bend as far as possible, as if picking up something off the floor. Return to an upright position and repeat the bend to the left.

At Home

If you are seated and have a lot of room to move, such as at home while watching TV, tone your core with exercises that move your legs. Perform a knee raise crunch to target your rectus abdominis. Sit with your back straight, feet on the floor and arms crossed over your chest. Exhale, raise your right knee toward your chest as you lean forward and contract your abdominal muscles. Maintain this position for one second and then return to the starting position. Repeat with your left leg, or perform the exercise by lifting both knees at the same time. A seated oblique twist improves the strength and tone of your obliques, along the sides of your abdomen. Sit and place your hands on the back of your head. Rotate your arms and torso to the right as you lift your left knee to toward your elbow. For added intensity, hold onto a barbell placed across your shoulders or a dumbbell in each hand at your chest.

On The Floor

If a back injury or pregnancy prevents you from lying face up to strengthen your abs, but you are able to get onto the floor, perform a reclining curl or a Russian twist as an alternative. For the reclining curl to target your rectus abdominis, sit with your knees bent and feet flat. Cross your arms over your chest. Lean back and then lower your torso until your back is an approximately a 45-degree angle from the floor. Maintain this position for one or two counts and then slowly sit up and return to the starting position. Add a twist to target your obliques. Sit with your knees bent, feet flat on the floor and slightly leaned back. Clasp your hands together in front of your chest. Rotate your arms, hands and torso as far as possible to the right. Return to the center and then rotate to the left. Extend your arms out from your chest with your palms facing each other. Hold onto a dumbbell, kettlebell or medicine ball to increase the intensity of both exercises.

Exercise Guidelines

Warm up before you perform any seated abdominal exercises with three to five minutes of full-body movements such as walking, dancing or marching in place. If you are at work, a quick walk to the restroom and back will increase your circulation prior to exercising. Complete one to three sets of 10 to 12 crunches, twists or abdominal hollowing. Once three sets of 12 are easy, add resistance in the form of weights such as barbells, kettlebells and dumbbells.