The Twitchers

Hello!

A busy week it has been indeed. Hope your Easter weekend went well. Leah
and I had a fantastic weekend. We got to relax, watch a little golf or
should I say "I" watched a little golf. : ) It was a good break from all
the rush that we have in our lives.

This week I wanted to share something about the long twitch and short
twitch muscles we have in our body. What are they and how important they
are.

Are you a better sprinter or distance runner? Many people believe that
having more fast and slow twitch muscle fibers may determine what sports
athletes excel at and how they respond to training.

Skeletal muscle is made up of bundles of individual muscle fibers called
myocytes. Each myocyte contains many myofibrils, which are strands of
proteins (actin and myosin) that can grab on to each other and pull. This
shortens the muscle and causes muscle contraction.

It is generally accepted that muscle fiber types can be broken down into
two main types: slow twitch (Type I) muscle fibers and fast twitch (Type
II) muscle fibers. Fast twitch fibers can be further categorized into Type
IIa and Type IIb fibers.

On average, we have about 50 percent slow twitch and 50 percent fast
twitch fibers in most of the muscles used for movement.

Slow Twitch (Type I)
The slow muscles are more efficient at using oxygen to generate more fuel
(known as ATP) for continuous, extended muscle contractions over a long
time. They fire more slowly than fast twitch fibers and can go for a long
time before they fatigue. Therefore, slow twitch fibers are great at
helping athletes run marathons and bicycle for hours.

What Causes Muscle Fatigue?

Fast Twitch (Type II)
Because fast twitch fibers use anaerobic metabolism to create fuel, they
are much better at generating short bursts of strength or speed than slow
muscles. However, they fatigue more quickly. Fast twitch fibers generally
produce the same amount of force per contraction as slow muscles, but they
get their name because they are able to fire more rapidly. Having more
fast twitch fibers can be an asset to a sprinter since she needs to
quickly generate a lot of force.

Type IIa Fibers
These fast twitch muscle fibers are also known as intermediate fast-twitch
fibers. They can use both aerobic and anaerobic metabolism almost equally
to create energy. In this way, they are a combination of Type I and Type
II muscle fibers.

Type IIb Fibers
These fast twitch fibers use anaerobic metabolism to create energy and are
the "classic" fast twitch muscle fibers that excel at producing quick,
powerful bursts of speed. This muscle fiber has the highest rate of
contraction (rapid firing) of all the muscle fiber types, but it also has
a much faster rate of fatigue and can't last as long before it needs rest.

Fiber Type and Performance
Our muscle fiber type may influence what sports we are naturally good at
or whether we are fast or strong. Olympic athletes tend to fall into
sports that match their genetic makeup. Olympic sprinters have been shown
to possess about 80 percent fast twitch fibers, while those who excel in
marathons tend to have 80 percent slow twitch fibers.

Are Athletes Born or Built?

Can Training Change Fiber Type?
This is not entirely understood, and research is still looking at that
question. There is some evidence showing that human skeletal muscle may
switch fiber types from "fast" to "slow" due to training.

What can I do to improve my performance?

Keep in mind that genetic differences may be dramatic at the elite levels
of athletic competition. But following the principles of conditioning can
dramatically improve personal performance of a typical athlete. With
consistent endurance training, muscle fibers can develop more and improve
their ability to cope with and adapt to the stress of exercise.

Is fiber type the number one factor that makes an elite athlete elite?

Fiber type is part of a great athlete's success, but it alone is a poor
predictor of performance. There are many other factors that go into
determining athleticism, including mental preparedness, proper nutrition
and hydration, getting enough rest, and having appropriate equipment and
conditioning.

That my friends is your TIP of the WEEK...

See you at the gym!

- - - -
Stephen & Leah Menya
www.LionsGym.com
952-474-7000