Answer:
To understand the role of creatine in the body, you first must understand that the body uses energy in the form of ATP (Adenosine triphosphate) which is basically Adenosine + 3 phosphate molecules. The body has the capacity to store and create it's own ATP using both anaerobic and aerobic metabolic production methods (2 anaerobic methods DO NOT require oxygen, 2 aerobic methods DO use oxygen).
The 2 methods ATP is produced within the Anaerobic Metabolism are called:
1. The ATP - Creatine / Phosphate Phosphagen System
2. Fast Glycolysis
The 2 methods ATP is produced within the Aerobic Metabolism are called:
3. Slow Glycolysis
4. Fatty Acid Oxidation
1. Within the ATP - CP Phosphagen Anaerobic Metabolism System there are 2 phases, the 1st phase is STORED ATP. The body stores very limited amounts of ATP (energy) in the muscle cell. During initial short duration activity or short intense activity immediate energy for muscle contraction comes from STORED ATP.
Here's how the 1st STORED ATP phase works:
A chemical bond is broken between the 3rd phosphate molecule releasing energy. It can be shown like this:
ATP produces ADP + energy + P or (A-P-P + energy + P)
There's only enough STORED ATP for a few seconds, then ATP must be recreated by the 2nd phase (Creatine Phosphate)
In the 2nd phase - the Phosphagen System:
Creatine Phosphate or CP is a high energy chemical compound also STORED in the muscle cell. The phosphate molecule breaks off this high energy bond and releases energy that rejoins the phosphate molecule onto ADP to recreate ATP.
In other words, CP produces Creatine + energy + P
then, ADP + energy + P produces ATP.
The total amount of STORED ATP and CP is limited to about 10 seconds of intense effort. Once the storage is depleted, the cell shifts to the next method of metabolism to make more ATP, and that is
2. Anaerobic Fast Glycolysis...
(BUT, what if you could deliver more Creatine & Phosphate to this Phosphagen System - could you increase the storage, lengthen the depletion time, AND increase the available energy in the resting state? In other words, could you increase this phase 1 and phase 2 STORED energy production time before having to move on to the Anaerobic Fast Glycolysis and Aerobic methods of ATP production?)
From 10 seconds of activity to about 2 minutes, our system breaks down carbohydrates in the form of glycogen stored in the muscle cell or glucose found in the blood. This process is called glycolysis. Utilizing glucose or glycogen creates energy in the form of ATP. (1 unit of glycogen/glucose creates 2 units of ATP). |
