The holidays are upon us, but that doesn’t mean your fitness plan has to take a back seat to the tempting foods and their consequences that can materialize around this time of year. Now is as good a time as any to “exercise” extra pounds with some focused abdominal work. Of course, if are serious about your abdominal training and expect results, you must eat a clean diet (abs really are made in the kitchen) and elevate your metabolic rate to help consume the adipose (fat) tissue that may take up residence on your waist.

A weight-training workout will elevate your metabolic rate for several hours, even after your last set or stride has been completed, so it is very important that you don’t miss any time in the gym. You will also need to step it up a bit by adding 30-50 minutes of cardio each training day. Assuming that you are in good health, the cycling, or running/walking should be intense enough to push your heart rate to 70 percent of your maximum (your predicted maximum heart rate is 220 minus your age).

If you have the time, the best approach is to do your cardio at a different time of day than your weights, because this will give you two chances to increase your metabolic rate each day. If your schedule is just too hectic to do this, then pack both your weight and cardio workouts in on the same day, because that is better than missing out on either part of your training quest.

Superior abdominal exercises will always shorten and tighten the fibres in the front and/or sides of the abdominal wall and they will never stretch the muscles. It is important to stay away from exercises that have excessive stretch components to them. The curl-up crunch will do exactly that, by inducing strong contractions which will tighten and firm your waist.

Muscles Used

The rectus abdominis muscle is the primary anterior abdominal muscle that is activated in curl-up crunches. The rectus abdominis is split into left and right halves by the linea alba, a thin tendon-like vertical line. Usually, there are three or four rows of horizontally placed tendons running across the rectus abdominis. The short fibers of the rectus abdominis run from one horizontal tendinous insertion to the next. If both right and left halves of the rectus abdominis muscle contract at the same time, the trunk is flexed forward. In the case of the curl-up crunch, this is achieved as your head and chest move closer to your hips.

The oblique muscles on the side of your waist are also activated by curl-up crunches, albeit to a lesser extent than the rectus abdominis. The external oblique muscle has two halves. Each half runs from the lower ribs by small bundles of muscle fibres that are angled in the same direction that your fingers would point if you were to put your hands in your pockets. When both the left and right sides of the external oblique muscles work together, they flex the trunk and move the head toward the feet.

The internal oblique muscle sits just deep into the external oblique muscle. It attaches to a thick connective tissue sheath in the lower back and also to the iliac bone of the hip. Its fibres run around the side of the trunk at right angles to the external oblique muscle and attach to the lowest three or four ribs. Similar to the external oblique muscle, if both left and right portions contract together, the internal oblique flexes the trunk at the waist and moves the head toward the feet.

Curl-Up Crunches

1. Lie on your back on the floor with your knees bent to 90 degrees or a little more. Your feet should be flat on the floor. Do not anchor your feet, as this would allow your hip flexors to help with the movement, thus decreasing the effect for the anterior abdominal wall. Cross your arms loosely across your chest.

2. Exhale as you lift your upper body (shoulders and mid-back) from the floor. Curl your shoulders forward in a slow, deliberate manner (i.e., not fast or jerky) and tuck your chin to your chest as you come upward. This will help to get you into the practice of a curling type of crunch. You do not want to come upward like a flat board, because this does not cause enough shortening of the fibres in your abdomen.

3. Most people will not be able to come up too far, especially at first, but this is fine; just go as high as you can in good form. If you have particularly strong abdominals, you will be able to lift your lower back from the floor. If you are able to do this, do not lift your torso higher than a 45-degree angle with the floor. Hold the top position for a count of two.

4. Slowly return to the starting position by uncurling your shoulders and upper body and inhaling as you come down. However, do not pause or rest once you get to the starting position, but immediately curl your upper body forward and resume the crunch part, by trying to lift your upper body from the floor.

As your abdomen gets stronger and tighter, you can increase the intensity by holding the top position for up to 4 seconds in each repetition. Another way to elevate the intensity for the internal and external oblique muscles is to add a slight twist to one side, then the other as you are coming upward on successive repetitions. Be sure to make the twist slow and not fast. Moving your feet closer to your hips will also make this exercise harder to do. And finally, as you progress and your abdominals are really getting in shape, you can make the exercise more challenging by placing your fingers along the side of your head (not behind your head) instead of on your chest.

You should work up to 3 sets of slow 25-30 repetition curl-up crunches. However, do not expect to do this quickly, as it will take a while before the abdominal fibres can handle the demand. By combining curl-up crunches with a tighter diet, and frequent cardio and resistance training, your thin, tight and flat abdomen will be ready for display soon!

References:

Agur A., M. R., K.L. Moore, AM Agur. Essential Clinical Anatomy by Third Edition, Lippincott Williams & Wilkins, April 2006 ISBN: 078176274X

Gidaris, D, Hatzitaki, V, & Mandroukas, K (2009). Spinal flexibility affects range of trunk flexion during performance of a maximum voluntary trunk curl-up. J Strength Cond Res, 23, 170-176.

Parfrey, KC, Docherty, D, Workman, RC, & Behm, DG (2008). The effects of different sit- and curl-up positions on activation of abdominal and hip flexor musculature. Appl Physiol Nutr Metab, 33, 888-895.

Pischon, T, et al. (2008). General and abdominal adiposity and risk of death in Europe. N Engl J Med, 359, 2105-2120.

Vera-Garcia, FJ, Flores-Parodi, B, Elvira, JL, & Sarti, MA (2008). Influence of trunk curl-up speed on muscular recruitment. J Strength Cond Res, 22, 684-690.

Vera-Garcia, FJ, Grenier, SG, & McGill, SM (2000). Abdominal muscle response during curl-ups on both stable and labile surfaces. Phys Ther, 80, 564-569.

Workman, JC, Docherty, D, Parfrey, KC, & Behm, DG (2008). Influence of pelvis position on the activation of abdominal and hip flexor muscles. J Strength Cond Res, 22, 1563-1569.