Muscle Physiology Continued

I would like to continue my discussion on the physiology of human muscle by talking about the chemical reactions that produce the energy required for human movement. Food is broken down within segments of our cells called mitochondria in a process known by the name metabolism.

The eventual result is the production of a chemical called adenosine triphosphate or ATP. It is the removal of the phosphate molecule from this chemical that causes the release of energy required for muscle contraction. Some of the food is broken down into a sugar referred to as glucose, with the remainder stored in a form called glycogen that can broken down into glucose as the body requires it.

These stores of glycogen are what fuels our bodies during long endurance exercises, and depletion of these stores during physical activity is called "bonking" or "hitting the wall." To avoid this occurrence, you should drink an energy drink containing small amounts of sugar to replenish these stores if the activity is longer than one hour. I always make it a point to take along a bottle of energy drink with both small amounts of sugar and electrolytes when going out for long bike rides.