Turning on the Glucose Sink: How to Train to Lose Body Fat.

Yesterday, I presented a new way to look at fat loss training, in terms of 'signaling' how energy is partitioned. I described how the lack of insulin in type 1 diabetes essentially shunts glucose right out of the body without ever being taken up by the muscle, organs, or fat. This metabolic disturbance not only changes your body composition, but can kill you. Again, adequate energy is ingested, however the hormonal signals are faulty.

While type 1 diabetes is an autoimmune disease of the pancreas, non-diabetics can experience the effects of impaired energy partitioning. We all know the disappointing effects of aging on body composition; just about everyone will gain body fat and lose muscle mass. Or, more energy is partitioned to the body fat stores, and less is partitioned to the muscles.

The most common 'treatment' for this worsening body composition is to go on a caloric-restricted diet. The result, if the individual can keep it up for a significant length of time, is less energy for muscle and body fat stores. BOTH muscle and fat tissue diminish to a point. Then, usually the power of hunger exerts itself, and food intake increases.

The Shift In Emphasis

Plenty of research shows how futile this approach is (after a year). Some people can maintain it, but I'd put my money on people gaining it back in a year.

Instead of 'starving' our fat (and muscle) tissue, the emphasis should be placed on signaling the body to partition more energy into the muscles, and less into the body fat stores. Of course, this is under precise, complex, physiological control, too. Luckily, we know how to manipulate these physiological control mechanisms: with strength training.

If you ever look at those guides to how many calories are burned for a given physical activity or exercise, strength training is usually in the middle or lower on the list. But, they fail to mention how strength training affects the physiological control of energy partitioning. Strength training (that is a progressive program designed to improve strength and muscle mass, not crunching and toning your arms with three-pound dumbells) produces a glucose sink. Energy (glucose) is signaled into the muscle at a greater rate with strength training(and less is available to be shunted into the bodyfat stores) because the muscles have a greater demand DURING AND AFTER a session. Physiologically, anabolic hormones trigger growth and uptake of energy (glucose) to support that growth. This is mediated by increased insulin sensitivity. That means your muscle (and liver) cells have been signaled to more effectively use insulin and more energy is partitioned into the muscles and less to the bodyfat stores.

Strength training is one of the few 'tools' we have to manipulate how our body partitions energy. In effect, it can help reverse the profound metabolic disturbances seen in our 'western society.'

Next, I will discuss nutritional strategies that help improve energy partitioning.