In a nutshell, this paragraph describes the relationship between (the lack of) exercise and what is known as “metabolic syndrome”, characterized by excess body-fat (especially at the waist) and chronically high blood sugar levels.
Human beings require periodic bursts of high muscular effort. In the absence of such activity, glycogen is not drained out of the muscles to any meaningful degree. When this state is coupled with routine consumption of large amounts of refined carbohydrates, a level of glucose is produced that can no longer be stored in the muscles. The muscles are already full, because an insufficient number of glycolytic fibers have been tapped. Glucose therefore begins to stack up in the bloodstream, and the body’s insulin levels rise. Because the glucose cannot get into the muscle cells, the receptors on the surface of those cells become insensitive to insulin. The body then produces even more insulin and now has large amounts of circulating glucose and large amounts of circulating insulin. That glucose gets transported to the liver, where, in the face of high insulin levels, it will attach to fatty acids (triaclglycerol), and all future carbohydrate ingestion now is partitioned exclusively to fat storage.
The excerpt is from John Little and Doug McGuff’s interesting book, Body by Science. “One of the best ways” to reverse this situation, according to Little & McGuff, is to engage in regular high-intensity exercise that exhausts the muscles. They prescribe a specific, weekly, high-intensity 12-minute weight-training workout to achieve this, and have seen spectacular results for their clients.
I would add that carbohydrate restriction — removing sugar and grains in particular — should help considerably!
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