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Why Cross Country Causes Injuries

Cross country running has the highest rate of injuries of all high school sports. The injury rate is even higher for girls than for boys. The extremely high injury rate is caused by asking runners to train and race in the same week. Most coaches know that you have to run very fast in practice to run very fast in races and the fastest way to train is to run intervals or fartlak, a series of short very fast bursts of running interspersed with slow jogging.

Training is done by running very fast on one day, have your muscles feel sore on the next day, and not running fast again until your muscles feel fresh. The faster you run, the longer it takes to recover. Most high school runners take at least a week to recover from the soreness caused by a race. The coach typically takes them to a race on Saturday and asks them to run intervals on Monday or Tuesday, before they have recovered from the race. They are either injured by that interval session or else they are injured by racing the next Saturday, before their leg muscle have recovered from the interval session. If they run fast in races and slowly all the time in practice, they are less likely to be injured, but more likely to run slowly in races.

The most effective way to prevent injuries is for a coach to set up at least two teams. Let each team race on alternate weeks, so each runner races on one week and trains fast twice in the next week.


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Dear Dr. Mirkin: Are fructose-sweetened sports drinks better than those made with ordinary sugar?

No; fructose is not better for you than table sugar, and drinks that contain lots of fructose can cause intestinal gas. Fructose is a single sugar molecule, while granulated white table sugar is called sucrose and is made up of two single sugars, glucose and fructose bound together. When table sugar reaches your intestines, the double table sugar, sucrose, is immediately split into its single sugars, glucose and fructose. Almost all of the glucose is absorbed immediately into your bloodstream. In the presence of glucose in your intestines, most of the fructose is also converted to glucose, which is rapidly absorbed into your bloodstream. Regular sugar is absorbed so quickly that very little remains in the intestinal tract. However, when you take fructose without glucose, the fructose is not converted as rapidly to glucose, and the fructose is absorbed less quickly into the bloodstream. Therefore, some fructose passes along the intestinal tract until it reaches the colon where bacteria can ferment the fructose to cause gas and cramps. This is particularly important when you take fructose before or during exercise. Exercise speeds up the rate that fructose reaches your colon and increases your chances of getting gas pains and cramps.


Dear Dr. Mirkin: You say that fructose is not absorbed as well as table sugar. I'm diabetic; doesn't that mean that fructose would be better for me?

Again, no; several studies show that taking large amounts of fructose can harm a diabetic. Diabetes occurs when the body lacks insulin or cannot respond to insulin. Insulin is supposed to drive sugar from the bloodstream into cells. When insulin does not do its job, the sugar, glucose, accumulates in the bloodstream, causing a diabetic to feet sick and weak and even pass out. Fructose can get into cells without insulin, so some people incorrectly recommend that diabetics eat foods made with fructose. However, in the intestines and the bloodstream, fructose is converted into glucose, and the diabetic gets no benefit.

Not only is fructose of no benefit to a diabetic, it can cause harm. Glucose causes fat cells to release leptin that makes you feel full, and prevents the stomach from releasing ghrelin that makes you hungry. Fructose does not affect leptin or ghrelin, so it increases hunger to make you eat more. Large amounts of fructose can block the body's ability to respond to insulin, so even more insulin is required. Furthermore, the liver converts fructose far more readily to a body fat called triglycerides, than it does with glucose. High triglyceride levels raise blood levels of the bad LDL cholesterol and lower blood levels of the good HDL cholesterol, which increases heart attack risk. The treatment of diabetes includes avoiding all types of sugar and other refined carbohydrates, losing weight if overweight, and exercising. It is not treated by eating fructose.


ASPARAGUS season is here! Cook them until just crisp-tender in your steamer and serve with a lemon wedge, or use them in these recipes:
Asparagus-Shrimp Salad
Creamy Asparagus Soup

List of Diana's Healthful Recipes


June 26th, 2013
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About the Author: Gabe Mirkin, MD

Sports medicine doctor, fitness guru and long-time radio host Gabe Mirkin, M.D., brings you news and tips for your healthful lifestyle. A practicing physician for more than 50 years and a radio talk show host for 25 years, Dr. Mirkin is a graduate of Harvard University and Baylor University College of Medicine. He is board-certified in four specialties: Sports Medicine, Allergy and Immunology, Pediatrics and Pediatric Immunology. The Dr. Mirkin Show, his call-in show on fitness and health, was syndicated in more than 120 cities. Read More
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