Of Cells And Skiing
Over the last month or so I've been busy cursing the various
aches and pains of "old age" and trying to recall if I'd ever
had problems with my hamstrings in high school. It seems that
running workouts have for some reason signaled some of my muscle
groups to go on strike now and again, an experience that I can
rarely recall as a young athlete. More recently, I've had the
rare luxury of being able to ski on actual snow prior to Thanksgiving,
and this has caused me to make acquaintance with a few other
muscle groups that haven't had as much attention in awhile.
In the moments spent babying these muscles and promising myself
that I'd stretch more frequently, I've had a chance to reflect
upon my old friend, cell biology (Quick, now's your chance to
escape:).
As athletes, we attempt to make ourselves better in some
way at the sport in which we are participating. Perhaps it
is increasing our endurance, building up our speed, or working
on explosiveness and strength. Many times this is a process
of working our muscles and other tissues hard, tearing them
down slightly, rearranging, and rebuilding. Maybe it is fine-tuning
some aspect (or multiple aspects) of our technique. It may
be training our bodies to give the correct stimuli to make
a more efficient aerobic system. All of these things rely
on signals that we send to the cells and tissues in our body,
instructing them to behave in certain ways. Every so often,
our enthusiasm (or lack of proper conditioning) gets the better
of us and we overdo it. Damaged tissues holler out, "Wait
up-we need a break!" Then they put up "Under Construction"
signs while they rebuild and repair the damage. Those waiting
periods, not unlike experiences in automobile traffic around
road construction, are mentally difficult for most of us,
but critical as well. It may just be your run-of-the-mill
sore muscles or a more serious strain or pull; in either case
we need to let these little cellular road construction crews
do their work so that we can resume our normal exercise routine.
At the most basic level, cell biology parallels the fundamental
balance that we try to achieve during training. Cells are
designed with an elaborate system of checks and balances,
a system that beautifully orchestrates a cell's behavior and
life span. Muscle cells represent a particularly extraordinary
example of regulated function, and their tasks are ones that
we typically take for granted with each breath and each glide
on skis that we make. Our hearts, representing one type of
muscle, become the ultimate engines for us, providing the
power that we rely upon to glide across the flats or to motor
up a steep hill. While composed of individual cells, special
lines of communication--sort of like old-fashioned party lines--provide
for rapid passage of information between neighboring cells.
This allows for coordinated regulation of the heart as a whole,
so that it can most efficiently pump the all-important oxygenated
blood to your hungry muscles. While the heart continues this
wonderful process virtually without our conscious input, we
have the opportunity, through exercise, to increase the strength
of this marvelous organ and ultimately the force with which
it can deliver its precious cargo.
Other muscles, such as those in our double-poling triceps
and skating quadriceps provide another beautiful example of
cell biology at its finest. These skeletal muscles are also
composed of many individual cells and mini-contractile units
that have figured out that it is more efficient to work together
rather than separately. Through a complex set of events, involving
rapid delivery of information from our nervous system, these
tiny independent "micro-muscles" generate a concerted effort
to contract a muscle or group of muscles and move an arm attached
to a ski pole or leg with a ski extended from it. They do
so in a beautifully coordinated way and often with split-second
timing. So, each time you decide to flex that tricep muscle
for a strong double-pole, your brain is initiating a lightning-speed
signal, carried through a nerve cell, that ultimately contracts
the muscle in your arm-- this involves the coordinated activation
of several hundred thousand individual muscle cells in virtually
a simultaneous fashion! And just as with the heart muscle,
it is within our power to train our skeletal muscles to become
stronger, to better utilize oxygen, to be more efficient in
energy storage and production. We can even stimulate the growth
of the capillary beds surrounding the muscle tissue so that
more oxygenated blood can be made available.
Just as with our bodies as a whole, we need to care for
our muscular system during exercise in order for it to work
properly. We must supply the muscle with energy as well as
plenty of oxygen. When the muscle runs out of these important
resources, we begin to run into difficulties. At the larger
scale, we feel pretty pooped out, are short of breath, begin
to feel the muscle burn. At a smaller scale, our muscles are
also feeling taxed, as their food and energy and oxygen supplies
begin to deplete. When our muscles are "new" to a particular
activity (or out of shape, as many of mine are), the supply
and rapid availability of food and oxygen is not as great
as in someone who is highly trained for that activity. Luckily,
the memory of our bodies for particular learned activities
is very strong-we don't have to continually relearn HOW to
ski, we just need to increase the power of our engines. Fortunately,
our efforts through exercise are able to encourage those muscles
and their supporting cast to become stronger, to fatigue a
little less quickly, and to perform the same task with a little
more speed and power. Once again, so many of these events
seem to take place with hardly a thought on our part. We are
able to glide and stride and climb hills on our skis because
our muscles and nerves are coordinated in a way that allows
us to complete these tasks in a few moments rather than in
a few weeks.
So, when an injury or onset of muscle soreness occurs, even
though it may be slight, it is a good time to sit back and
appreciate how hard those cells are working for us (yet another
thing to be thankful for over this Holiday weekend). We can
overwork our muscles and experience that good old delayed
soreness, appearing 24 hours or so after the fact. We can
also have more serious pulls and strains that get our attention
even more. At a microscopic level, damaged cells are sending
out chemical signals left and right, recruiting in the road
crews to tend to the microtears and subsequent inflammation
and swelling that often occur as a result of the damage. Repair
mechanisms begin, including calling in some new recruits,
new muscle cells that can help to begin rebuilding and strengthening.
Often, the little road crews can perform their repairs without
serious impedance on the flow of our general busy lives, but
sometimes we are forced to slow down a little more, obeying
the 30 mph signs and single-lane traffic zones until all is
back to normal.
The human body is truly a marvelous thing. It is incredible
to realize the job that a particular cell carries out during
its given life-span, to appreciate the efficiency with which
it carries out its duties, and to realize that it coordinates
its tasks with those of other cells to form functional units
of tissues, organ systems, and entire individuals. The notion
that we can actually train, through physical exercise, our
cells to behave in different ways is truly remarkable. Hopefully
we can all limit the times that our muscles are undergoing
repair this season so that we can enjoy the ski trails to
our full potential. Be kind to your cells-treat them well,
because they are working hard for you!
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Margaret is married to Bruce Adelsman, and they have two young boys
who hopefully will be future cross-country skiers. She skied competitively
at Bemidji High School and Bemidji State University during the 1980's,
and then in some citizen races in the early 1990's while in graduate
school. She hopes to share new commentaries on a periodic basis
related to various aspects of life as a cross-country skier.