Spot Reduction Myth
Contrary to what the infomercials suggest there is no such thing as spot reduction. Fat is lost throughout the body in a pattern dependent upon genetics, sex (hormones), and age. Overall body fat must be reduced to lose fat in any particular area. Although fat is lost or gained throughout the body it seems the the first area to get fat, or the last area to become lean, is the midsection (in men and some women, especially after menopause) and hips and thighs (in women and few men). Sit-ups, crunches, leg-hip raises, leg raises, hip adduction, hip abduction, etc. will only exercise the muscles under the fat.
Lower Abdominal Myth
It is widely believed the lower abs are exercised during the leg raise or other hip flexor exercises. However, it can be misleading to judge the mechanics of an exercise based on localized muscular fatigue. The primary muscle used in hip flexion is actually the Iliopsoas, one of many hip flexors. The Iliopsoas, indeed, does happen to originate deep below the lower portion of the Rectus Abdominous. During the leg raise, the entire abdominal musculature isometrically contracts (contracts with no significant movement) to:
* Posture the spine and pelvis
o Supports the weight of the lower body so the lumbar spine does not hyperextend excessively
o Maintains optimal biomechanics of the Iliopsoas
+ Hips are kept from prematurely flexing if the lumbar spine and pelvis does not hyperextend excessively
+ Iliopsoas can contract more forcefully in a relatively slight stretched position
# Bent knee (and hip) sit-ups actually place Iliopsoas at a mechanical disadvantage
* Counteracts Iliopsoas's pull on spine
o Many people with weak abdominal muscles are not able to perform hip flexor exercises without acute lower back pain or discomfort
The combination of the local muscular fatigue, or a burning sensation from the isometrically contracted abdominal muscles, and from the working hip flexors produces fatigue in the pelvis area which we mistakenly interpret as the lower portion of the Rectus Abdominous being exercised. In movements where the Rectus Abdominous does Isontonically contract (contracts with movement), it flexes the spine by contracting the entire muscle from origin to insertion. The spine is not significantly flexed during the leg raise. Incidentally, both the spine and hip flexes during the Sit Up and Hip Raise. See Spot Reduction Myth above.
But there is nothing in my diet that is outlandish or weird, nothing that requires a trip to the hippy store, or anything like that. Three meals a day plus some snacks (but the snacks are small, and almost always fruit, or a small bowl of tortilla chips if I want something salty). No "fourth meal" or midnight snack late at night. I eat plenty of meat (although I only buy it from small-scale local producers, mostly for ethics, but maybe there is a health implication?) and dairy, but maybe half of my meals are vegetarian, not by plan but because that is the best-tasting way to cook what is in the fridge.
To be honest, I don't know if this actually tells you anything. The sizes of my portions probably matter more than what I'm eating, as does what exercise I do or do not get.
posted by Forktine at 7:06 AM on May 27, 2007