Power-endurance and Mitochondrial density

Power-endurance is the term climbers use when they are referring to doing sustained powerful moves throughout a route. Developing this is an essential muscular adaptation for climbers wishing to exceed their current level and to be well rounded. To understand what adaption is actually taking place here, we need to look into cellular chemistry and exercise physiology. Let's start with the mitochondria.

Mitochondria are the little powerhouses that produce ATP (the basic energy currency of muscle) through the process of oxidation. But before energy get's to this aerobic (with oxygen) step of metabolism it must first start as glycogen stored in the muscle. Glycogen in cleaved from the cell through a process called glycogenolysis during heavy exercise. It is then broken down into glucose, where it enters the cytosol, or liquid portion, of the cell, and experiences several anaerobic (without oxygen) chemical reaction to be broken down into ATP and pyruvate. Pyruvate is then transferred from the cytosol to the mitochondria, where it is further broken down to ATP. During strenuous exercise, the anaerobic reactions cycle faster and produces more pyruvate than can be used by the mitochondria. This leads to a build-up that is transferred into the blood stream as lactic acid. During this phase, your muscles feel a burning sensation and quickly become fatigued.

So, the issue we face at this point is clear; the cytosol is producing more pyruvate than the mitochondria can handle, causing byproducts of fatigue to quickly accumulate, which results in termination of the muscular contraction.

 I layman's terms, you fall off the wall!

Given this information, the logical necessary adaption to continue energy production and prevent muscular failure is to increase the capacity and density of mitochondria within your muscle fibers. Sounds simple, right? Well we'll see. . .

Okay, so next, you need to produce power! Power is force x acceleration. How do muscles increase in their ability to produce power? Well, let's understand physiologically how power is produced. In essence, it is the recruiting of as many muscle fibers as possible in sync to cause the greatest force over the shortest period of time. The application to climbing is when one propels himself with great speed in order to utilize momentum when moving between two holds spread far apart.

As with all adaptions, powerful climbing in and of itself, will produce more power. However, in order to create an adaptation of any kind in your muscles, the stimulus must be provided to momentary muscular failure in order to produce optimal results. If you reach failure on a climb, and it is not in the pulling muscles of your body doing powerful movements (but rather a failure in technique, pump or core tension) then little in the way of increased power will result. If you specifically want to develop power in your pulling muscles and you want to do it in minimal time, you need to train with weights to pure muscular failure.

So again, power-endurance is the ability to sustain powerful movements throughout a sport route. If this is what we are after, then it is logical (albeit to my knowledge, theoretical) that we develop power in a manner that causes an increase in mitochondrial density. If the muscle fibers required to produce powerful movement (mostly FG or type 2 fibers) are to continue to function over an extended period of time, then an increase in mitochondria is necessitated to metabolize all available energy and endure. My theory is not yet complete, but I have two articles that give a good place to start. Please read them and give me your thoughts. Increasing mitochondrial density and Negative accentuated power