good
read this also, which the portion in blue is for your
purview:
munfitnessblog.com ::
Should I Still Exercise Even
When I Have Cold or Flu?

Early last month, I was not feeling well for couple of days.
Having sore throat and cough. But, I was wondering whether I should
push myself to pump the iron. Just now, managed to catch an
interesting conversation with a seasoned personal trainer.
Here is what I have learned:

Though Mun has always encouraged you to exercise, but do not
feel bad if you are not able to do so when you are sick. It is not
the end of the world if you take some time off to rest.
Missing a week of workout will not deteriorate your fitness
level significantly. Trust me, you do not have to start
all over again. The gym building will not run away.

In fact, when we under weather, we should eat well,
drink water, rest and not to do strenuous physical
activities to avoid extreme fatigue. When we are sick, our muscles
are not working but our immune system will be working hard.
Even if you have cold and still decide to run or cycle, if you do
not feel well, stop exercising immediately and rest. Do not keep
pushing yourself for the wrong reason. Also, if you are infected by
virus, do not go to gym. No body will come up to you and
say thank you for sharing your infection.
Hopefully, this above and below the “neck rule” will help you to
decide whether you should exercise. However, always listen
to your body. In fact, we should exercise to stay healthy
before we get sick and not only wait till we have cold then only we
want to exercise. Don’t you think so?
