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LESTER HOLT, Anchor: The Olympics are a chance to marvel
at the physical abilities of the athletes.
But what makes them unique?
After all, they're made of the same flesh and blood as the rest of us--
how did they become Olympians?
UC-Berkeley's Dan Fletcher, a bioengineering researcher funded by
the National Science Foundation, has some answers.
HOLT: The speed of JR Celski.
J.R. CELSKI, U.S. Speed Skating Team - Short Track: We're at speeds of
35 or 45 miles per hour.
HOLT: The strength of Julie Chu.
JULIE CHU, U.S. Hockey Team: You're really putting a lot of energy into the swing.
HOLT: The agility of Rachael Flatt.
RACHAEL FLATT, U.S. Figure Skating Team: You only spend about
a half second in the air.
HOLT: Even the control of John Shuster.
JOHN SHUSTER, U.S. Curling Team: You're actually trying to deliver the rock
with a specific weight on a specific line.
HOLT: More than just a showcase of one athlete's amazing physical
gifts, the Winter Olympics are also a unique chance to witness the
dazzling physiology of all human movement.
Dr. DAN FLETCHER, University of California, Berkeley: The remarkable thing for me
is the ability to even carry out the activity--to do the ski jump,
to skate around sharp corners.
It's that coordination of the muscles, the nerves, that to me is a
fascinating thing to watch.
HOLT: Dan Fletcher, associate professor of bioengineering at
U.C. Berkeley, has a unique view of human movement.
Using special high power microscopes and other cutting edge technology,
Fletcher's lab studies how individual cells move within the
human body--such as this video of white blood cells hunting for
infection by sniffing out bacteria--and the role cells play not just in
human movement, but also in maintaining good health and
combatting damage and disease.
FLETCHER: You can actually watch cells crawling around.
And you might not think about it, but there's movement in the body constantly.
And it's not just blood flow. There's movement in tissue as well.
HOLT: The goal of Fletcher's research is to understand not just
the mechanics of how cells move, but what role they play in fighting
disease and maintaining good health.
FLETCHER: If we can understand the parts,
if we can understand how they're put together,
maybe we can actually understand what it means for a cell to move and
what it means to help that cell repair tissue.
HOLT: At the molecular level, cell movements depend on the assembly of
tiny filaments called actin, and the action of molecular motors, called myosins.
FLETCHER: These molecular motors are small individual proteins that
consume energy, much like the pistons in an engine.
These molecular motors consume a fuel and then they
convert that fuel into a motion.
HOLT: In the case of muscle cells, billions of these myosin motors pull
on bundles of the actin filaments, generating muscle contraction
and body movement.
To understand how this works, the motors and fibers can be isolated
and studied, as in this movie showing actin filaments pulled
along a surface by myosins.
FLETCHER: These all have to be coordinated.
You need all of your muscles, all of your molecular motors,
to be contracting in unison, in order for the muscle to contract.
HOLT: But how do muscles go from simple contractions to the dynamic
motion that allows Emily Cook to do her twists;
Kris Freeman to endure a 15-kilometer race;
or Lindsey Vonn to attack the the Super-G?
The simple answer: practice.
LINDSEY VONN, U.S. Ski Team - Alpine: You're constantly working,
working, working.
You work all summer and you're training all the time on hill and off hill.
HOLT: One way practice helps is by strengthening key muscles--a
surprisingly complex process that involves actually breaking down
muscle tissue through rigorous exercise,
tissue which the body then repairs and makes stronger.
FLETCHER: Damage is a critical part of how we grow.
The damage generated in muscles has to be repaired and it's the body's
ability to repair and improve that muscle that leads to building the muscles.
HOLT: Another way practice helps is by teaching those key muscles to
memorize how they should perform during a specific task--a phenomenon
called "muscle memory" that involves both the muscle and the brain.
FLETCHER: As you go through exercises,
particularly repetitive exercises, even something as simple as typing,
we remember where that "W" is, and it seems second nature.
HOLT: While typing is easy for most people,
skating, snowboarding or skiing at an Olympic level is not.
To perform these tasks at such a high level requires years and years
of intense practice.
EMILY COOK, U.S. Ski Team - Freestyle: I've been jumping for
probably close to 18 years.
I've been a gymnast for almost 25 years.
So you know, after your body's been trained,
you don't have to think so technically about that stuff.
HOLT: Which is why the Winter Games are a unique chance to celebrate
human movement at its finest.
FLETCHER: We all have the same muscle fibers,
we all have the same muscle motors, but it's through training that one
develops the organization that's necessary for the exquisite motion
that we see Olympians have.
HOLT: Organization that starts at the molecular level
and ends with the physical triumph of the Olympics.