Gabe Mirkin, M.D.
Warming up does not prevent muscle soreness. The only way you can prevent the muscle soreness
is to stop exercising when your muscles start to feel heavy and hurt, but stopping then will keep you
from becoming a better athlete.
Muscle soreness is caused by damage to the muscle fibers. It is not caused by tightness, lactic acid
buildup, cold muscles or swelling, so muscle soreness cannot be prevented by stretching, cooling
down, warming up, or by taking aspirin.
Muscles contain two types of fibers: white fibers that govern strength and speed, and red fibers that
govern endurance. When you exercise vigorously, most of the damage occurs in the white strength
and speed fibers. To strengthen these fibers, you have to exercise intensely and through discomfort,
which allows the fibers to tolerate greater forces on them and helps you to become stronger and
faster, but it also causes soreness. So, all athletes train by stressing and recovering. On one day, they
exercise hard and fast. On the next day or two, their muscles are sore. They do not exercise
intensely again until the soreness disappears.