Dr Michael Chia
Assistant Professor & Exercise Physiologist
School of Physical Education, NIE, NTU

Developing and strengthening the abdominal muscles should form the basis of any strength development conditioning program. Indeed, abdominal and lower back muscles should be developed prior to performing several lower-body and upper-body exercises (Aaberg, 1998). It is important to strive for balance in developing abdominal muscles. That is to say that the lower back muscles must also be developed concomitantly as you develop your abdominal muscles. An imbalance in muscle development can be a recipe for injuries. They are many benefits in developing strong abdominal and lower back muscles-improved posture, reduced risk of lower back pain and better sports performance in activities that require running, kicking or jumping. Previous research has demonstrated that a reduction in the muscle endurance of the abdominal muscles is highly correlated with the occurrence or recurrences of low back pain (Rissanen, Alaranta, Saino and Harkonen, 1994). It is therefore important to strengthen and improve the endurance of the abdominal muscles.

The abdominal muscles are a group of muscles that comprise the rectus abdominis (front portions of the 'abdominals'), the internal obliques, the external obliques and the transversus abdominis (side portions of the 'abdominals'). Research has established that the transversus abdominis and the internal obliques are responsible primarily for the stabilisation of the lumbar spine (lower back), and acting primarily as the spinal prime movers are the rectus abdominis and the external obliques (Warden, Wasweilner and Bennell, 1999).

In training to develop abdominal muscles, or for that matter, any group or groups of muscles, it is prudent to adhere to the following recommendations in order to harvest optimal benefits with minimal risk of injuries.

• In designing your own strengthening routines, be sure to select exercises that train the body in a balanced fashion.

• Strengthen any weak links prior to progressing to more challenging exercises.

• Do not compromise on the proper way of doing the exercise especially when fatigue starts to set in. Pay close attention to maintaining the proper alignment, body position, motion and technique of the exercise

• Always breathe during all resistance-training exercises. The rule of thumb for breathing for most exercises is to inhale as the active muscles lengthen (on relaxation) and to exhale as the active muscles contract (on effort)

• If you are in doubt about the safety of any exercise, consult with a qualified fitness professional

• Get your doctor's advice first if you had any previous injury or serious illness before attempting any exercise training, or if you are unsure of your present health status

• Keep your training exercises interesting and fun to keep monotony at bay. You can do this by introducing variety to your training program, manipulating the order of the exercises, exercising with a partner, or by exercising to your favourite pieces of music

At this point it is appropriate to mention that simply developing and strengthening the abdominal muscles will produce the desired results, namely "abs to die for". Abdominal exercises are best combined with aerobic-type exercises such as walking, jogging, cycling, aerobic dancing, skating using Rollerblades, or swimming. If done frequently enough, they will help you lose body fat whilst maintaining the mass muscle that you will develop with your strength conditioning program. Reducing your salt intake will also help enhance the "visibility" of the muscles that you have developed.

In strengthening and developing abdominal muscles, you may wish to consider the following exercise:

Exercise tips

• Keep the lower back firmly pressed against the back pad or mat throughout the exercise.

• Work slowly, move one vertebra at a time, and keep the tension in the abdominal muscles.

• Keep the head and neck in the neutral position throughout the exercise.

• When supporting the neck muscles with the palms of the hands behind the head, do not pull on the neck. From time to time, it may be useful not to support the neck, as the muscles in the neck are typically weak links and also need to be strengthened. However, it should be noted that the muscles of the neck, being smaller and weaker would tend to tire before the abdominal muscles.

Alignment and body position

• Lie on an inclined, flat or declined bench or platform with the lower back pressed firmly against the pad or exercise mat.

• Place legs on a chair, bench or any stable object or brace the feet against a wall to create about 45-90 degree angle between the trunk and the legs.

• Spread the feet apart so that the feet are pointed at about 10 o'clock and 2 o'clock in order to limit hip flexor involvement.

• Cross the arms over the chest and brace the hands under the chin to limit neck movement

Technique

• Contract the abdominals. Begin by pulling the rib cage up and toward the hips, attempting to move one vertebra at a time

• Continue to pull the rib cage up and towards the hips until the abdominals are fully contracted whilst keeping the lower back firmly pressed against the exercise mat or pad.

• Hold, continue to contract the abdominals, and breathe out any remaining air

• Slowly lower the trunk one vertebra at a time to the original start position, whilst maintaining the tension developed in the abdominal muscles.

Reverse abdominal curls
Reverse abdominal curls or crunches are another multiple-joint motion exercise that targets the rectus abdominis and like curls and crunches, the reverse version can also be performed at a inclined angle, flat or on an declined angle. Leg placement can also add or decrease the overload of the exercise.

Exercise tips

• Keep the shoulder blades pressed firmly against the back pad or exercise mat throughout the exercise.

• Avoid arching the back at any point.

• Work slowly, moving one vertebra at a time whilst keeping tension in the abdominals.

• Keep the neck and head in the neutral position throughout the exercise.

Alignment and body position

• Lie on an inclined, flat or declined-angled bench or platform with the shoulder blades and lower back pressed firmly against the pad.

• Keeping the legs together, flex the knees and hips to form a bout a 90 degree angel or set them at the desired overload (i.e. the further the legs are placed away from the body, the greater is the overload).

• Firmly hold on to the back or sides of the platform or stationary object to anchor the upper body down.

Technique

• Contract the abdominals. Begin by pulling the rib cage up and toward the hips, attempting to move one vertebra at a time.

• Continue to pull the hips toward the rib cage until the abdominals are fully contracted and the hips are rolled up slightly off the exercise mat or pad.

• Hold and continue to contract the abdominals, and breathe out any remaining air.

• Lower the trunk and hips slowly, one vertebra at a time back to the start position whilst maintaining the tension in the abdominals.

Abdominal rotations
Abdominal rotations are a multiple-joint motion exercise that targets the external obliques. The alignment of the external obliques is such that they contract diagonally. Hence to target this group of abdominal muscles, a certain degree of trunk flexion should follow the rotation. Abdominal rotations can of course be performed at an inclined angle, flat or at a declined angle to offer the required amount of overload. These exercises are normally reserved for athletes who are interested in strengthening this multi-joint motion for their particular sport.

Exercise tips

• Hold the hips and buttocks stationary once they have been properly positioned.

• Work slowly and gradually by maintaining the tension on the obliques and abdominals.

• Keep the head and neck in the neutral position throughout the exercise.

Alignment and body position

• Place one hand on the side of the body opposite the legs and with the other hand behind or by the side of the ear so as to slightly support the head.

• Keeping the legs together, flex the hips and the knees. Rest them on a chair, bench, or any stable object or support.

• Rotate the hips and pelvis to one side whilst keeping the trunk and upper body straight.

• Begin with the shoulders slightly off the floor and keep tension on the abdominals.

Technique

• Contract the abdominals and obliques. Begin by pulling the rib cage up and over towards the hips.

• Continue to pull the rib cage toward the hips until the abdominals are fully contracted. The trunk and upper body should be aligned straight with the angle of the pelvis.

• Hold and continue to contract the external obliques and the abdominals. Breathe out any remaining air.

• Slowly lower the trunk to the start position.

Training frequency, repetitions and sets

• Training frequency refers to the number of training sessions per week. The recommendation is to have three training sessions per week, alternating with rest days between them. This is important as adaptation to any training stimulus occurs during the recovery period.

• One repetition is the complete execution of the exercise in good form. Start with 10-15 repetitions and progress up to 25.

• One set of the exercise may be 10-15 repetitions for beginners who are starting out and up to 25 repetitions for advanced exercisers. Complete between 3 and 5 sets per training day (you can of course, break up the training day into several sessions), always giving yourself enough rest between sets (usually between 3 and 5 minutes, but longer if necessary) to complete each set of exercises in good form.

References:

1. Aaberg E (1998). Muscle Mechanics. Human Kinetics.
2. Rissanen A, Alaranta P, Saino H & Harkonen H (1994). Isokinetic and non-dynamometruc tests in low back patients related to pain and disability index. Spine 19: 1963-1967.
3. Warden S, Wajswelner H & Bennel K (1999). Comparison of Abshaper and conventionally performed abdominal exercises using surface electromyography. Medicine & Science in Sports & Exercise, 31: 1656-1664.

Date reviewed: 25 February 2000