Performance Training
The Difference Between Slow-Twitch and Fast-Twitch Fibers | The Difference Between Slow-Twitch and Fast-Twitch Fibers | | Print | |
| Written by Rado | |
| Wednesday, 27 September 2006 | |
|
Today's lesson is about skeletal muscle fibers. Learning the difference between slow-twitch and fast-twitch muscle fibers will give you a better understanding of how different exercises and workouts will benefit you.
To begin with, there are many different types of muscles in your body. Some work involuntarily, like the heart muscle...it works without you having to tell it. Our focus will be on the skeletal muscles - the muscles that move your bones, or your limbs and body around.
In short: Your skeletal muscles are made up of 3 different kinds of fibers: Type I - red fiber, SLOW-TWITCH muscles. They are slower-contracting fibers (weaker) but they are very efficient at using oxygen to create energy without lactic acid buildup. Think of these as "weaker" muscles with tons of endurance, and can go on forever. These fibers are used for high-endurance events like marathons. Type IIa - these HYBRID fibers are a mix between Type I and Type IIb fibers, they have a very high contraction rate (making them very strong and explosive), and yet very energy efficient therefore making them very resistant to fatigue. They are found infrequently in humans and are very helpful for all types of physical performance. Type IIb - these are the pure FAST-TWITCH fibers, white fibers, that contract very quickly (making them very strong and explosive) but they also tire out very easily.
Further explanation: Every person has a different percentage makeup of the different muscle fibers in their body. These percentages are genetically determined and they will aid people accordingly. A "normal" person would be expected to have roughly 50% of type I muscle and 50% of type II muscle. It isn't surprising to discover that Olympic sprinters have 80% Type II muscle fiber and Olympic long distance runners have 80% Type I muscle fiber! So as you can see, everyone already has a genetic makeup that makes their body more suitable for one type of sport or physical event over another. Finding out what your body is good at would be a great way to excel in your sport. Do keep in mind that Type II fibers are not "stronger" than Type I fibers. Pound for pound, they are equal strength. Type II fibers are simply FASTER, meaning that they contract at a faster rate and can therefore handle a higher intensity workload needed to be more explosive, or lift heavier, or do more work.
Some final questions: Q: Can you change your muscle fiber type by training? A: There haven't been too many studies that support this but there has been some recent evidence that those with PURE fast-twich fibers Type IIb can transition to the "hybrid" Type IIa fibers with constant endurance training.
Q: Can I target different fibers with specifc training?
Final Advice: Comments
(15)
researcher
written by Harvey , August 05, 2008
Is there any difference between fast twitch and slow twitch muscle fibers in t erms weight?f
Votes: +1
report abuse
vote down
vote up
re:muscle weight
written by bean , January 26, 2009
In response to rado, muscle bulk on weightlifters isnt from muscle fibre type, but the simple fact they are lifing weight to get bigger, whereas an endurance runner isnt bulking. A better example would be olympic sprinters compared to olympic marathon runners.
Votes: -1
report abuse
vote down
vote up
is ugly
written by sasha , February 05, 2009
sasha looks like jimmy
Votes: -5
report abuse
vote down
vote up
bri
written by heyy , February 05, 2009
brianna love triston and ronal
Votes: -5
report abuse
vote down
vote up
loves
written by clarissa , February 05, 2009
clarissa loves jason
Votes: -4
report abuse
vote down
vote up
she luvvs saul a lot
written by lilly smells , February 05, 2009
she doesnt wash her clothes at alll
Votes: -4
report abuse
vote down
vote up
she does wash her clothes
written by lilly , February 05, 2009
so do i she always does so do i
Votes: -2
report abuse
vote down
vote up
-
written by ingo , March 26, 2009
hi ,
Votes: -2
how can i avoid that my fast twitch fybres turn to slow twitch? thx report abuse
vote down
vote up
I love everyone
written by Jay , December 08, 2009
i love this boy and my boyfriend but the other boy love has a girlfriend he is in love with and i dont even think he likes me anymore....what should i do??
Votes: -2
report abuse
vote down
vote up
...
written by sexyyyy chicken :D , February 04, 2010
ARR SUMWUN LET ME SUCK THEIR BOOBSS :D
Votes: -1
report abuse
vote down
vote up
WE LOVE MUSCLES
written by cassie , February 15, 2010
mmm biceps
Votes: +0
report abuse
vote down
vote up
|
| < Prev |
|---|
| Nutrition |
| Dieting |
| Supplements |
Question 7:
What is the most important factor in creating muscle strength:
Set volume
Gravitational force
Exercise form
Rest period between exercises
Question 8:
Fast twitch muscle fiber (white or TypeII) has a maximum speed of contraction rate of:
32mm/s
42 mm/s
50 mm/s
28mm/s