Sunday, October 7, 2012

Performance Adaptations

If you spend any time talking to evolutionary scientists, they'll
tell you that an organism's structure evolves to cope with the
stresses to which it is subjected. This idea has led to the theory
of adaptation -- that an organism's structural design is regulated by
its functional demand. Remarkably, structural changes also occur in the short term in response to exercise training: bones increase their density, muscle fibers increase their metabolic efficiency, and cardiac muscles grow stronger. If the quantity or structure incorporated into our system is matched to what is needed, it's logical the amount of change that takes place to match the increased need. And that's exactly what happens when we train.

Following a training stress, your body adapts and physiologically
overcompensates so that the same stress, when encountered again,
does not cause the same degree of physiological disruption. In
short, your body adapts to be able to handle the stress. Following
the adaptation, your body can do more work. The aim of training,
therefore, is to introduce training stimuli in such a fashion that
higher and higher levels of adaptation are achieved. If you
repeatedly threaten the body's survival, you will cause adaptations
to be made to counteract the threat. A classic example of this is
the long run of marathoners. Repeatedly running for long periods
of time (longer than two hours), presents a threat to the muscles'
survival by depleting their storage of preferred fuel (glycogen,
the stored form of carbohydrates). If you run out of fuel, the
muscles say, "Hey, this person is running for so long that I don't
have any more fuel. I won't be able to survive. If this activity
is going to be a regular habit, I need to make more fuel." So,
guess what happens? When you consume carbohydrates following
your long run, you respond to the empty tank by synthesizing and
storing more glycogen than usual in your skeletal muscles, thus
increasing your storage of fuel (and therefore your endurance)
for future efforts. Imagine if you kept driving your car until
the gas tank was empty and your car responded to that threat by
making its tank bigger so it could hold more gasoline. Pretty
efficient adaptation.

Unfortunately, our ability to adapt to a training stimulus doesn't
keep occurring indefinitely. There will come a point, which is
specific to each person or athlete, when more training, at best, does not lead to better results and, at worst, causes injury. The main difference between Olympic athletes and the rest of us is that Olympic athletes continue to make physiological adaptations with more and more training, though the increases become micro adaptations at some point.

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