Ask Doctor Cory.

Dear Dr. Cory:

Why do we have muscles?

Hannah Gay

Peoria, Illinois

Dear Dr. Cory:

I am a gymnast. When I work hard, my muscles hurt. Why is that?

Ricardo Ramos

Sacramento, California

Dear Hannah and Ricardo:

Some muscles help the body move by pulling on bones. Other muscles work inside the body to pump blood, let you breathe, or help digest your food.

Muscles use oxygen and food from the blood that runs through your body. When muscles work hard, they burn that food and oxygen too quickly for the waste product, lactic (LAK-tik) acid, to be carried away by the blood. This buildup of lactic acid can cause soreness or cramps.

Warm Your Form

Exercise soreness can be eased by warming up, stretching, and cooling down after a workout.

Stretches should not be bouncy or painful. Stretch until you feel tightness in the muscle, but not pain. Then hold for about thirty seconds and relax.

If you are trying to build up your muscles, go slowly. Muscles need time to build strength. The more you use them, the longer they last. They get better at using the oxygen and food brought by the blood, and they get better at removing the waste products.

Easy muscle activity, like slow swimming, jogging, or fast walking, in the days after activity, can improve circulation to the muscles and help muscle soreness, if there is no muscle injury.

Dear Dr. Cory:

Sometimes when I put my head underwater, some water goes into my ears. Then the next day my ears start to hurt. What should I do to stop this from happening?

Concepcion Bastida

Colton, California

Dear Concepcion:

Water trapped in the outer ear can make the skin soft. This makes it easier for bacteria to get into the skin and grow into an infection commonly called "swimmer's ear."

The ear will have to be treated with prescription medicine and kept dry to get rid of the infection.

To Help Prevent: Swimmer's Ear:

* Don't use cotton swabs, especially of you tend to get swimmer's ear. The swabs remove the earwax that protects your ears from moisture and bacteria.

* Dry your ears carefully with a towel. Tilt your head from side to side and gently pull your ear in different directions to help the water run out.

* Consider buying over-the-counter eardrops to use after swimming to help prevent swimmer's ear. Or your family can make their own drops by mixing equal parts of white vinegar and rubbing alcohol. Apply two to four drops to each ear after swimming.

However, if you have frequent ear infections, have one now, or have ever had a hole in your eardrum, please see your doctor before using any type of eardrops.

Sincerely, Cory SerVaas, M.D.

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