Do you ever wonder why some runners are just born to sprint while some are born to endure? I remember joining a biathlon race in a relay category at Farrer Park. I managed to lap a famous Singapore sprinter in a 4.5 km run. Nothing to be proud of. Wait till he asked me for a duel in a 100 meter sprint.

What I am trying to say, sprinters are just born to sprint and long distance runners are just meant to run far. If you really look into microscopic view of a muscle, you can tell the difference. There are two main types of muscle cells, or fibers in the human body.

These muscle cells are different in colours. These two types of muscles are called Type I and Type II. Type I is red in colour and Type II is white in colour. The logic from the colour of the muscles is due to the amount of blood it contains. And blood carries oxygen, therefore, the movement of this red muscle is much slower.

And as for the Type II, which is the white muscle, does not need oxygen to move, which make the movement much faster. And in type II there are three categories of muscles, which is called Type IIa, IIb and IIc. I will go through that into details.

Although Type I moves slower than Type II, but Type I last longer. Therefore, it can make you run long distance. Sprinters have about 26% Type I muscle while elite distance runners have 79 to 88% of Type I muscles. Type I produces aerobic movement while Type II produces anaerobic movement. Sprinter use mostly anaerobic. A short burst of super fast and strong energy, while long distance runner uses mostly aerobic.

Some scientist believed that to break a sub two hour marathon, a long distance runner may have 50% of each muscles type. The runner need the speed as well as endurance to run that fast.

Can different muscle types be developed through training? What do you think?

Reference:
Lore of Running by Tim Noakes

Photos:
http://kidshealth.org
http://www.lionden.com/muscle_animations.htm