DEAR DR. DONOHUE: I am a three-sport athlete and am good but could be much better if I could run fast. How can I improve my running speed? – J.A.

ANSWER: There are two important elements to speed: stride length and stride frequency. Stride length is the distance taken with each step. Stride frequency is the number of steps taken in a given time period, like a minute. There’s a third important factor in speed. It’s genetic endowment. Speed greatly depends on the number of fast-twitch muscle fibers a person is born with. That’s something over which you and I have no control. We have some control over the other two elements.

Lengthening the stride is tricky business. If the steps become too long, they throw a person off-balance, something that doesn’t enhance speed. To arrive at an optimum stride length, some coaches suggest measuring the length of the leg, multiplying that length by 2.5 and then aim for a stride length that is at least 60 percent of that figure. A runner can simplify matters by making a conscious effort to increase stride length every time he or she runs. Then it becomes second nature, and speed increases.

Stride frequency – the number of steps taken – is important, but not as important as stride length. Rapid rope-skipping is a good exercise for improving stride frequency. So is downhill running. However, beware. Downhill running is very taxing on leg muscles. Overdoing it can strain muscles – especially when done by a novice.

Arm movement is another factor in speed production. Powerful arm swings give the body momentum and increase speed. When the right foot is forward, the left arm should be forward, and vice versa. The arm should be drawn backward forcefully, and the forward thrust should be such that the hand rises to shoulder level.

DEAR DR. DONOHUE: I am 15 years old, and I pitch for my high-school team and for a summer traveling team. Last year, in the middle of the season, I developed pain and stiffness on the inside of my pitching elbow. I believe the condition is called medial epicondylitis. How can I prevent this injury so I can pitch the whole season? – A.T.

ANSWER: Medial epicondylitis is the right terminology, but it’s often called golfer’s elbow. Let’s give readers an idea of what you’re talking about. With the arm hanging down and the palm facing forward, the medial epicondyle is the bony projection at the side of the elbow next to the body.

Epicondylitis is an inflammation of the tendons, muscles and ligaments that attach to that area of bone. Close to 50 percent of professional pitchers have evidence of changes in that area. Repeatedly throwing a ball at high speeds stresses the muscles and tendons there, and that leads to pain and sometimes to the formation of scar tissue. Scar tissue can limit elbow motion.

For active inflammation, rest is important. Early on – in the first two days – application of ice to the medial epicondyle calms things down. The ice should be applied for 15 minutes three or four times a day. Then switch to heat, either moist or dry. Anti-inflammatory medicines also soothe the inflamed tissues. When pain leaves, throwing can resume but at a low intensity.

You can prevent a return of epicondylitis by strengthening your arm muscles. While seated, support your forearms on your thighs. Let your hands project past the knees. Hold a 1-pound weight in each hand and twist your hands clockwise and counterclockwise 10 times. Repeat the exercise twice with a short rest between each set of exercises. As you get stronger, increase the amount of weight, but do so gradually.

DEAR DR. DONOHUE: Some people are confused about steroids used illegally by athletes to build muscles and cortisone-type steroids used for things like nasal allergies and asthma. Would you say a word about this? – J.L.

ANSWER: “Steroid” is a word designed to confuse people. One kind of steroid is male hormones, illegally used by some athletes to build muscles. An entirely different kind is anti-inflammatory hormones, like cortisone and its many relatives. These steroids do not build muscles. They suppress inflammation and have many justified uses.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475. Readers may also order health newsletters from www.rbmamall.com.