Fasting and insulin sensitivity

One way of thinking about muscle growth is that you are trying to make your muscles fat. Fat cells store energy - as do muscle cells; however energy from fat cells is for the slow burn while energy from muscle cells is for the quick burn.

In order to get fat muscle cells, you exercise to deplete their reserves anaerobically, then you replenish them. Part of the way in which muscles replenish is to become insulin sensitive and pump glycogen into the muscle cell fluid. Insulin sensitivity can be increased by exercise induced gylcogen depletion.

I was curious - Would fasting before an exhaustive workout increase the supercompensation of glycogen in muscle tissue? What would be the effects on insuline levels, insuline sensitivity, glycogen transport into muslce tissue.

Apparently, it is a bad idea to fast before exercise. Although fasting and exercise both increase insulin sensitivity (versus insulin resistance, or diabetic), fasting will just make you fat.

The data indicate that intermittent fasting and physical training may increase insulin action via different mechanisms because muscle energy stores did not change with the present fasting intervention. (J Appl Physiol 99: 2128-2136, 2005. )

In other words, fasting before exercise and then replenishing does not cause muscle cells to supercompensate (ie get bigger), but it does cause fat cells to supercompensate...