Abdominal Work — Common Misconceptions (Gym & Class Setting)

Abdominal work may be the best single fitness activity a trainer can advise for clients, yet members rarely flock to classes geared to it. Three reasons: (1) people are generally confused about the varied benefits of abdominal work; (2) once known, the benefits of even intense abdominal work are not immediately visible, though they can be felt subjectively; (3) people tend to work their abdominal muscles inappropriately — they don't know how to work them, or don't know when they're training for coordinated strength (with the back and hips) versus isolated strength and tone.

Misconception: potbellies and below-the-navel tummies are removed by abdominal work. Fat bellies and tummies are emptied of fat by decreasing caloric intake (particularly calories from fat) while increasing energy demand — not by ab exercises. The only "tummy thinning" effect that can be expected from strong, toned abdominals is holding in the body's internal organs (particularly the stomach and intestines), which might otherwise protrude. (See transverse-abdominis for the muscle responsible for this compressive/support function, and spot-reduction / adipose-tissue-rule for why the fat itself only comes off through an overall deficit.)

Misconception: more repetitions in abdominal work make the waist smaller. Not so. Many repetitions add to the stamina of the abdominals and have a place in an overall toning and fitness program, but hammering away at crunching and twisting the trunk does not make the waist smaller — just more shapely when the abs are contracted and tissue fat-level is low.

Misconception: sit-ups and leg raises produce a trim waist. Much of the contrary: traditional straight-leg sit-ups and leg raises work the hip flexors (iliacus and psoas — the iliopsoas), and with too much upward movement can lead to lower-back problems instead of abdominal tone. (See iliopsoas-lordosis-situp for the full lordosis/hip-flexor mechanism and how to minimize it — e.g. rising less during the sit-up.)

Misconception: sit-ups make the lower back strong. Not really — not unless the abdominal work is focused on the internal oblique and transversus abdominis (the inner abdominal muscles). These muscles help the lower back because of their anatomical association with the thoracolumbar fascia: the very muscles the lower back comprises (psoas, quadratus lumborum, erector spinae) emanate from the spinal column and are held in place by the fibers of this fascia, which is in turn fixed by the internal oblique and transversus abdominis pair. The greater the tone in these inner abdominal muscles, the greater the stability in the lower back. (See internal-oblique and transverse-abdominis for the muscle-level detail.)

Misconception: abdominal muscles aren't like other muscles, and are very difficult to strengthen and condition. Abdominal muscles are skeletal muscles and can be conditioned and made stronger like any other. However, they are slow to condition unless exposed to repeated challenge, and slow to strengthen beyond their given tone level unless resistance is applied to their movement — resistance can come from free weight, cable weights, pressure from a partner, bodyweight on an incline bench, or slow controlled movements with mental concentration. Anything less than a regular, planned program of abdominal work tends to yield no visible change ("my gut's not better than before").

• Three reasons ab classes underperform: confusion about benefits, benefits not immediately visible, inappropriate/uninformed technique (coordinated vs. isolated strength).
• Potbellies are removed by a caloric deficit, not ab exercises; the only real "tummy thinning" effect of strong abs is holding internal organs in place.
• More reps build stamina and tone, not a smaller waist.
• Straight-leg sit-ups/leg raises train the hip flexors and, with excess upward movement, risk the lower back instead of building ab tone.
• Sit-ups strengthen the lower back only when they emphasize the internal oblique/transversus abdominis, via their thoracolumbar-fascia connection to the lumbar spine.
• Abs are ordinary skeletal muscle — they respond to resistance and a regular, planned program like any other muscle group; sporadic bodyweight work alone conditions slowly.

• abdominals — the muscle group these misconceptions concern.
• transverse-abdominis — the "holding organs in" mechanism.
• internal-oblique — co-stabilizes the lower back via the thoracolumbar fascia.
• iliopsoas-lordosis-situp — the hip-flexor/lordosis mechanism behind the sit-up myth.
• spot-reduction — the parallel myth that localized exercise removes localized fat.
• adipose-tissue-rule — the caloric-deficit arithmetic that actually removes a potbelly.