Did you ever wonder how Arnold Schwarzenegger got those abs in his movie Pumping Iron? He has the same muscles as you and I do, but most of us would never believe it.
Abs is the nickname that refers to the muscles of the abdominal wall. Anatomically, your trunk (the midsection below your ribs) is made up of five sets of muscle groups; four of them are in the front (the abs) and the other is in the back. The five muscle groups work together allowing us to flex forward, extend backward, twist a little, and flex to one side and the other. The specific muscles and the motions they produce are:
- The rectus in the middle front — bending forward at the waist and bending over to one side or the other
- External oblique — bending over to one side or the other
- Internal oblique — bending over to one side or the other
- Transversus — squeezing the ribs down toward the waist
- Erector spinae — extending backward at the waist
Most people immediately think sit-ups when they hear abdominal-muscle exercise. But sit-ups primarily work only one of the abdominals, the rectus. What you want is a program that works all the abdominal muscles. There are over 200 different active and isometric abdominal maneuvers to choose from.
I recommend starting with a routine that you will repeat regularly. Once the exercises start to feel a little easier, you can add variety.
How often one should do abdominal exercises is debated. Some trainers suggest doing them daily, others prefer every other day. Personally, I try to do 10 to 15 minutes of dedicated abdominal exercises at least five days per week. Sometimes I do them before aerobics or resistance training and sometimes as the last part of my workout. Any time is a good time to do abs.
Here are a few abdominal exercises to get you started:
Modified sit-up — Lie flat on your back; bend your knees so that the soles of your feet rest comfortably on the floor close to your buttocks. Place your fingertips just behind your ears. Take a slow deep breath through your nose and out through your mouth. Repeat this a few times to get a rhythm. Inhale to prepare and exhale as you slowly bring your shoulders up off the floor. Do not lead with your head as this creates strain in the neck rather than tightening the abs. You only need to raise your shoulders about 6 inches off the floor to engage the upper rectus. (As you get stronger, you will aim to get yourself as high as 30 degrees off the floor, but no higher.) Continue to slowly breathe out, holding the position for one to two seconds, and then inhale as you come back down. The key is slow and controlled. Repeat the movement six to 12 times. And then do another set. With all of the exercises, you will gradually increase your number of repetitions.
Lower abdominal crunch — Lie flat on your back with your hands behind your head or your arms at your side, whichever is more comfortable. Lift your legs and bend your knees so that you have a 90-degree angle between your lower abdomen and upper thigh and a 90-degree angle at your knees. Keep the knees together and continue to look straight up at the ceiling. Inhale as you pull your knees in toward your chest while pressing your low back flat against the floor. Hold the inhale for a full second and then exhale as your let your legs slowly move back to the starting position. Do not rock. Feel your lower abdominal muscles, especially the lower rectus, engage as you move your legs in and out. Do the same number of repetitions and sets as with modified sit-ups. The more advanced technique is to hold your legs straight and count to four before pulling your knees back in. Go slowly and stay in control.
Oblique crossovers — Lie flat on your back with your hands behind your ears. Lift your legs and bend your knees so that you have a 90-degree angle between your lower abdomen and upper thigh and a 90-degree angle at your knees. Inhale to prepare. Raise your shoulders a couple of inches as you start to exhale. While keeping your elbows back, reach your right shoulder toward your left knee as you feel the right side of your abdomen (right oblique) contract. Remember to push your low back down towards the floor as you come up. Hold for one to two seconds at your top. Then inhale as you slowly reverse the movement back to the floor. Inhale to prepare. Now do the same type of motion with the left shoulder going to the right knee. Continue to alternate side-to-side for six to 12 reps. Take a short rest and do another set. (If you get too tired holding your legs up, you will still work the obliques with you feet flat on the floor instead.)
Plank (optional) — This is an isometric exercise commonly practiced in yoga. As the name of the position implies, you will make your body as straight as a board. This exercise works all the trunk muscles as well as the shoulders and upper legs. Use a mat for this one and a mirror if available. Get down on your hands and knees. Rest your forearms flat on the mat, shoulder-width apart. Then straighten your legs as you go up on your toes. Keep your feet apart similar to your arms. Don't forget to breathe — in through the nose and out through your mouth. Slow and controlled. Push your elbows into the mat and lift your navel up towards your spine. Engage your abdominals and thigh muscles to keep yourself straight. The tendency is to keep your buttocks toward the air. Bring it down as you stretch through your legs, pushing your heels away from your head. Check your position in the mirror or ask someone to help make sure that you are flat. Hold this for 10 to 15 seconds if you can. Take a rest and repeat again. As you get stronger, you will hold it longer. Also, you can make the plank more challenging by going up onto your hands with your arms straight.
None of these exercises should cause pain in the low back. If you experience new or increased pain, stop the exercise and check your body positioning. Don't persist if the pain occurs when you try again.
Ab exercises have been part of my regular fitness routine for four years. Although I may never have Arnold's abs — even with a lot of imagination — I feel stronger, sit straighter and stand taller. And my back, which has caused me pain in the past, is sure treating me better.
Howard LeWine, M.D. is chief editor of Internet publishing, Harvard Health Publications. He is a clinical instructor of medicine at Harvard Medical School and Brigham and Women's Hospital. Dr. LeWine has been a primary care internist and teacher of internal medicine since 1978.