During exercise, certain structural abnormalities can stress certain parts of your body excessively, thereby increasing your chances of suffering a sports-related injury.
The most common biomechanical factor that causes injury is improper rolling of the foot once it has struck the ground. This condition, known as excessive pronation, can afflict anyone in a sport that involves running -- from track and field to football.
When you run, you land on the outside bottom of your foot. You then roll toward the inside. This natural motion is called pronation and is good because it helps protect you from injuries. When you run, your foot hits the ground with tremendous force. Pronation helps disperse that force throughout your entire leg rather than concentrating the force in your knees, hips and back.
After you pronate, you roll back toward the outer part of the bottom of your foot. This action is called supination. Then, you raise yourself on your toes and step off to land on your other foot.
People who appear to have flat feet usually have normal arches, but they pronate excessively, causing the lower leg to twist inward too much. This can cause foot, leg and knee pain.
Also, people who appear to have high-arched feet usually have normal arches, but they were born with such rigid ankles their feet can barely roll inward. Their feet are, therefore, poor shock absorbers. This increases their chances of developing small
fractures in the bones of their feet and legs.
Q: Please settle an argument that's brewing in my office. Does alcohol make people better athletes and better lovers?
A: The only athletes helped by alcohol are shooters. Alcohol can steady their hands. However, alcohol also decreases endurance, which is important in most sports. It weakens the heart muscle, so less blood is pumped through the body. It increases sweating, so you dehydrate sooner. And it causes your muscles to use more carbohydrates, so you become fatigued sooner.
Drinking a small amount of alcohol may improve sexuality for very inhibited people by helping them relax. However, regular drinkers make love less frequently than non-drinkers do. Heavy drinking drowns sexual desire.
Q: I'm about to give up! I diet, lose a few pounds, then gain it back. This happens repeatedly. Am I better off being overweight?
A: A recent study published in the New England Journal of Medicine showed that people who repeatedly lose and gain weight are more than twice as likely to suffer heart attacks and premature death than those who have stable weights -- even if they are overweight.
Every time you lose weight rapidly, you increase your chance of forming gallstones.
And, every time you gain weight rapidly, your liver manufactures extra fat that passes into your bloodstream to form plaques in your arteries. These plaques can block the flow of blood, thereby increasing your risk of suffering a heart attack.
To lose and keep weight off, you need a plan to follow the rest of your life. And that's hard for many people.
Eating a relatively unlimited amount of very low-fat foods and alternating between two sports every other day, working out for 30 minutes each time, can reduce your weight permanently.
Dr. Mirkin is a practicing physician in Silver Spring specializing in sports medicine and nutrition.