HIT Training 101

The following is a point by point analysis of glucose as it is broken down in digestion, enters the cytosol cell and how High Intensity Training manipulates this process by a reduction in rest time.

1. Energy enters into the Cytosol (liquid portion of cell) in the form of glucose from carbohydrates.

2. Energy is metabolized anaerobically (without air) through a series of approximately 20 chemical reactions until it becomes a chemical known as pyruvate.  This is an example of an anaerobic metabolism.  The process is known as glycolysis.

3. Pyruvate is then moved into the mitochondria where it is metabolized by the Krebs cycle and the respiratory chain.  During this process, pyruvate is converted to 36 molecules of ATP (adenosine troposphere).  This is called aerobic metabolism.

4. The Krebs cycle/respiratory chain converts energy from ATP at a slow rate.  In contrast, glycolysis produces only two molecules of ATP and has the potential to cycle at an infinitely faster rate.

5. The following summary is important to note because of the sharp contrast in processes: The Krebs cycle/respiratory chain converts pyruvate at a slower rate because it must be converted into 36 molecules of ATP.  Glycolysis, on the other hand, converts pyruvate at a faster rate because it must only convert two molecules of ATP.

6. By using maximum muscular exertion, the glycolytic cycle accelerates and you begin to make pyruvate at a faster rate than the Krebs cycle/respiratory chain can convert.  This causes the pyruvate to "stack up” and is therefore converted to lactic acid.  This is the burning sensation in the muscle.

7.  The Cytosol cell processes the lactate (lactic acid) anaerobically, during glycolysis, by converting it into pyruvate.  It has now been converted into a chemical form which will allow it to enter the mitochondria where it is metabolized aerobically.

8. By pushing the process of glycolysis to perform at a faster rate, it in turn, forces the subservient Krebs cycle/respiratory chain to metabolize at a much faster rate.  This serves to reinforce the fact that during High Intensity Training (anaerobics), the cardiovascular system is called upon to assist in its efforts aerobically. 

9. It is a necessary reminder that what strengthens the muscular system must also strengthen the cardiovascular system.  They are inextricably bound together as master and servant and cannot operate independently.  If a steady state "aerobic” approach is taken, which by definition, VO2 is not at its maximum, an inadequate stimulus will be given and therefore an inadequate response from the Krebs cycle/respiratory chain to strengthen the cardiovascular system.

10. It is also noteworthy to recall that a proper threat to the muscular system through  maximum effort (absolute failure) will produce a proper strength response.  Likewise, when the cardiovascular system receives a proper threat  through maximum VO2 effort, it will also respond with newfound strength as it prepares for the next time it is threatened.