AITank: Fitness Explained

Published by rougeqc21

Step into a gym and what do you notice first? The big guys right. What some people can transform their bodies into amazes all of us at some point or another. Men who look like descendants of Hercules himself. It is only natural for us to want to try and imitate these icons of strength and fitness, but before you set about training to be nothing but huge, ask yourself this. Do you just want to be able to move weight around, or be strong and immensely quick, explosive as I like to call it. The difference is this, being able to jump higher, run faster and exert force in general faster versus being able to pick up a tree or car real slow, but able to. Ridiculous examples but I think you get the point. The mechanical difference is the types of muscle fibers we recruit to perform certain tasks.

There are two types of muscle fibers, fast-twitch and slow-twitch or TypeII and TypeI. Within the TypeII class there are fast-oxidative-glycolytic TypeIIa and fast-glycolytic TypeIIb fibers. Contrary to what some people believe, both exert the same amount of force, it is simply the rate at which they do so that varies. TypeIIb fibers, as their name implies, are primarily anaerobic by nature possessing larger stores of glycogen and the enzymes necessary for anaerobic respiration, meaning they operate without oxygen. Adding to their architecture they have few mitochondria, the primary structure that is utilized for aerobic respiration. TypeIIa fibers on the other hand possess the enzymes necessary for anaerobic respiration and glycogen stores, along with oxidative enzymes and more mitochondria. Think of them as a hybrid fast-twitch slow-twitch fiber that can still exert its force as fast as the fast-glycolytic fibers. This characteristic of the TypeIIa fibers means they will out endure their TypeIIb counterpart.

Sprinters rely on these fast-twitch muscles to explode with every foot strike, batters to engage their shoulders and forearms instantaneously and basketball players to explode with their quadriceps into the air for a rebound or to slam it. So what is the deal with slow-twitch fibers.

Slow-twitch or TypeI fibers are what keep a marathon runner going, or a triathlete on his feet. They sacrifice contractile speed for long term endurance by having a complex network of capillaries and vast quantities of mitochondria within their structure to facilitate aerobic respiration, which will always out endure the utilization of glycogen stores which deplete quickly (more on glycogen utilization in this previous post). The capillaries that entangle these fibers ensure a steady supply of nutrients to the mitochondria, the same way a steady flow of fuel will keep your vehicle going. Which type of muscle fiber do I want then? Well unfortunately you do not have much say in the matter.

Your genetics determines your muscle fiber composition for the most part. It has been shown though that after years of training, and yes I do mean years, TypeIIb fibers can transition to TypeIIa fibers. Actually biopsies of some elite athletes shows that after many years of training, they possess almost no TypeIIb fibers, meaning there is hope for creating a more elite YOU. Dedication to your training regimen is what is going to decide how successful this recruitment is. Stick to the explosive movements, your clean press, power cleans, jump squats and high pulls. Or on your normal exercises such as bench, uses intervals like 3-2-1. What this means is that when you are bringing the weight down to your chest take three seconds, so slow controlled movement, then hold for two seconds and explode up. There will be a detailed article on Explosive Strength regimens here soon.

Still confused? Think of it this way, birds legs, take a thigh for example are darker slow twitch fibers. They stand around and walk all day so they need these muscles to last. Their wings, are white meat, fast-twitch, ready to get them airborne if farmer john comes around looking for dinner.

With a proper routine, you too can train to be explosive, increasing your overall athleticism dramatically. Jumping higher, running faster, and being able to be quicker in all movements just gives you an edge that pure bulk does not. So examine your routine, mix it up every so often and train to be explosive.
Until next time.

Mar 06, 2008
Filed under: Lifting, Physiology, Training, explosive, fast-twitch, fibers, functional, muscle, slow-twitch