A Brief History of Metabolic Power
What makes a martial artist powerful? Is it the mystical energy passed on from master to student or is there some real physiologic basis on why training creates increasing feats of power and acquisition of unlimited skills.
SOURCES OF ENERGY
Our body needs glucose as a source of energy. It is stored in a compact form called glycogen. This is then broken down into individual glucose molecules. We quantitate energy production in adenosine triphosphate (ATP). This is the universal currency of metabolic energy, absolutely essential for any activity.
For normal activity, glucose is broken down in 10 steps of glycolysis resulting in 2 ATP s. This is done while our body is resting, sleeping and otherwise light work.
As we begin moderate exercise, our body begins to use oxygen to breakdown glucose through the Krebs Cycle producing a whopping 36 ATP s! This cellular respiration is directly related to the capillary density of our tissue. The greater the density, the greater the amount of energy that can be produced.
The greatest benefit of regular and intense training is the increase in the alveolar capacity (ability to take in oxygen) and capillary density in our tissue. We can become more powerful just through taking classes!
As our bodies begin to maximize the aerobic cellular respiration, lactate and hydrogen ions start to build up. We exceed the ability of this metabolic pathway and our bodies need to find a way to work without oxygen. We now enter the anaerobic pathway for ATP production.
Through the Cori Cycle, lactate gets converted to glucose in the liver. It is then transported back to the cell for glycolysis to produce 2 ATP s.
The more efficient our bodies are, the longer we can stay in this lactate metabolism. Eventually this system will be overwhelmed as the H+ ions build up in the blood stream sending the pH downward. When this happens we start to feel the burn, painful and poor response from muscular effort and labored breathing. Our body is telling us to slow down.
In summary, we have three levels of work we can do; aerobic, anaerobic, and lactate threshold. With regular training we can increase the duration of our aerobic endurance and improve our ability to recover past the lactate threshold. Lack of training (which means regular attendance in class!) leads to deconditioning, early fatigue and painful recovery.
OTHER FORMS OF ENERGY
There are other forms of energy available to our bodies. Most of our energy comes from glucose, but what do we do when that is not available? Fasting conditions lead us to use other sources of energy.
In extreme forms of fasting, our bodies will break down muscle and fat to convert it to usable energy.
But short of that extreme, we can use another source known as ketones.
The energy from ketone metabolism can be used by the body through the Kreb cycle.
We have so many ways to use energy. The most important thing to remember is that training and technique are crucial to being able to function at the highest level. An increase in the alveolar (respiratory) capacity and capillary density allows us to be more powerful. Simply through regular practice and repetition, we can all master this important part of body physics.