The immune system is pretty complicated, but
there are some things that are pretty easy to
understand. One is that mounting an immune
response costs your body energy and raw
materials like protein.
Let’s start off by looking at how exercise in
general influences the immune response.
Exercise can reduce stress. This is good
because stress decreases a person’s immune
response. When the body is using its resources
to mount a stress response, it directs energy to
get ready for “fight or flight,” not germ
fighting. People who exercise regularly get
fewer colds than “couch potatoes.” Good
nutrition, sleep, and keeping a healthy weight
also seem to support a good immune response.
But what if the exercise is excessive?
Athletes and researchers call
this “overtraining.” After a hard workout, the
body needs to replenish water. It may also need
to replace carbohydrates and electrolytes (but
probably not nearly as much or as often as
sports drink companies may imply). The body
also needs sleep because that is when it repairs
the tissues that are broken down by hard
workouts. It needs some protein to repair the
tissue as well. If a person overtrains, the
energy and raw materials get put toward repair,
and there may not be enough left for an
effective immune response. Pushing yourself a
little harder is how you improve, but if you
push yourself too much harder, for too long, you
may do worse.
Athletes who overtrain start to feel tired
all of the time, but may not be able to sleep
very well. They do not perform well in practice
and competition. They often have negative
moods. Their heart rate is higher than normal
when they are not exercising. They may lose
their appetite, even when they are losing
weight. Their immune systems are less active
and they are more likely to get colds.
If you are an athlete, you can monitor
yourself. Try keeping a log of your workouts,
how you feel, and how you are performing. A
runner may keep track of split times, for
example. Your resting heart rate will also be a
good measurement. When you wake up in the
morning, before you get up, measure your pulse
for 10 seconds, they multiply that by 6. The
easiest place to feel your pulse is the side of
your throat, just below your jaw. Write this
down in your log too. Only a doctor can
diagnose whether you have overtraining syndrome,
but this information will be very useful in the
There is no quick fix for overtraining. It
can take weeks or months to recover, depending
on how overtrained the athlete is and how long
they have been that way.
Don’t forget to wash your hands. You’ll
create less work for your immune system.
Thanks for asking,