Gabe Mirkin, M.D.
Most experienced runners can tell when other runners
are in shape just by watching them run. They look for efficiency,
a measure of how much energy is lost by wasteful movements
during running. You run with your legs and all of your other
movements are used just to balance your body. The main
reason you don’t fall when you are walking or running is that your
brain constructs a "center of gravity", a point around which all
movements on one side are balanced by equal movements on
the other side. For example, when your right leg goes forward,
your left arm goes forward and your right arm goes backward.
You do this without thinking and your movements are
automatically calculated in your brain.
A study from The Hospital of Laval in France shows that
even the best runners lose their efficiency when they become
fatigued (Journal of Sports Medicine and Physical Fitness, June
2006). Experienced runners have consistent stride length and
form. This study shows that with fatigue, their stride length
decreases and, more importantly, they start to lose form by
adding a significant amount of side-to-side movement that
wastes energy and does not drive them forward.
Running slowly does not teach your brain how to balance
your body when you run fast. Good form comes from practicing
running very fast in training. People who run slowly all the time
usually have poor running form. They waste movements that do
not help them move forward. For example, their feet often move
to the side after they raise their feet from the ground. Their arms
do not move loosely and comfortably to balance their bodies.
They may run with toes pointed outward, which is a sign of weak
shin muscles. If you want to improve your running form, run
faster a few times every week.
January 15, 2007