Muscle Fiber Types
You have three types of muscle fiber that make up your "muscles," and this is sometimes called muscle composition. The average person has approximately 60 percent fast muscle fibers and 40 percent slow-twitch fiber (type I).
There are two types of fast-twitch muscle fiber. The fast muscle (what the researchers call IIa) moves 5 times faster than the slow. And the super-fast (IIx) moves 10 times faster. And there can be swings in fiber composition, (Muscle, Genes, and Athletic Performance, September 2000, Scientific American, Jesper).
The following chart shows that while there are differences in muscle fiber composition, muscle types can be developed based on the way they are trained.
|Muscle fiber type||Average person||Sprint trained||Aerobic trained|
|Slow - (type I)||40%||40%||55%|
|Fast - (IIa)||50%||20%||40%|
|Super-fast - (IIx)||10%||40%||5%|
Sprinters have more of all three fiber types than average, and a higher percentage of the super-fast IIx. And endurance trained individuals have more slow muscle (type I). While we are born with slightly different muscle composition, the point is; super-fast muscle can be developed if exercised properly.
Why is this important?
Researchers show that anaerobic exercise (short, quick-burst, gets you out-of-breath) is the type of fitness training that increases HGH. And HGH is, without question, the most powerful anti-aging, and anti-middle-aging, body fat-reducing, muscle-toning agent known.
Yet, when we finish high school (perhaps with the exception of a few that compete in college and the small number that make it to the pros), we become slow-twitch exercisers at age 20. And this is a mistake! Many may continue developing slow-twitch muscle (less than half of your muscles) with weights and cardio at the gym, and with jogging. If you think about it, we are starting the muscle atrophy process (the wasting away of muscle) on half of our muscle fiber ... AT AGE 20! No wonder we have an obesity epidemic and this year, 650,000 Americans will hear their physician say, "You have diabetes."
The cure for the obesity crisis, the cure the middle-age somatopause (metabolism slow-down), the cure for insulin resistance and (in many cases) diabetes, and the cure for the high cost of healthcare--is so simple, we keep missing it.
The cure is natural. It's free. But it can't be done overnight because the muscle fiber needed to perform high-intensity anaerobic exercise has atrophied (wasted away) beginning for most at age 20.
There's great news?
You can build back your fast-twitch muscle fiber (slowly at first) by performing plyometric drills and weight-plyos to build the fast muscle (IIa) and performing sprinting types of training to build the super-fast (IIx) to the point where you can release HGH through fitness training.
The Take Home
You may need to be doing more than working your slow muscle fiber with typical weight training, cardio, and jogging. But don't neglect slow-muscle training because this is 40% of your muscle fiber, and to a degree, it serves as a base for the development of the fast and super-fast muscle fiber.
Add fast muscle training to your workouts and you can prevent this common fitness mistake.