December 2003

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The good run

By Kimberlee Barbour

(Editor’s Note: This is the second in a series on running marathons.)

Remember the legend that Pheidippides, a runner from Marathon, was said to have died in 490 BC after carrying the news of victory over the Persians to Athens?

Unlike Pheidippides, today’s marathoners are much better prepared and are also unlikely to have fought a battle before beginning their long jaunt. A little preparation and forethought can make the race more comfortable, however.

How much is 'too much' of a good thing?

John Cianca, MD, an associate professor of physical medicine and rehabilitation at Baylor College of Medicine in Houston, says it is possible for marathoners to become ill from drinking too much water.

Hyponatremia occurs when the concentration of sodium in the blood in the body falls below normal (measured as 135 millimoles per liter). The body is overwhelmed by increasing fluid levels and may malfunction in its attempt to regulate sodium levels.

Hyponatremia develops slowly and often after exercise has concluded. First, runners complain that they “just don’t feel right,” Cianca said. Then they start to get a headache, become irritable and vomit. Breathing becomes difficult. They may complain of respiratory distress or have seizures. If the person is not treated promptly, he or she could go into a coma or die. Seek medical attention immediately if symptoms occur.

"Factors that may increase the incidence of hyponatremia are hot weather, stress, pain, too many fluids and long periods of exercise," Cianca said. "We are beginning to think that the menstrual cycle has an effect on the incidence of severe hyponatremia in women."

"The most frustrating thing about hyponatremia is that it is completely preventable," Cianca said. "People need to be educated on exactly what hyponatremia is and ways it can be prevented. Knowing your body and how much water it needs while exercising is necessary while training."

Every body is different and loses different amounts of fluids during exercise, Cianca said, and this makes it difficult for physicians to set standard fluid replacement guidelines.

Weighing before and after a workout is the first step to learning how much water the runner’s body needs for exercise. Be sure to towel off sweat before reweighing.

For every pound lost, a person should drink 16 ounces of fluid. If weight gain occurs, too much water was taken in and the runner should cut back on fluid intake next time. The next step is to design a personalized training program and take into consideration personalized fluid intake.

The problem with hyponatremia is that runners may not even know they have it until after the race when it could become fatal.

"More and more participants are running for charities and are not in the most favorable condition to run a marathon," continued Cianca. "Because many of these participants are walkers or running slowly, they have time to grab a couple of cups of water at each drink stand and are out in the heat for longer periods of time. They believe that they are working harder than they actually are and overcompensate in their hydration thereby increasing their chance of hyponatremia."

"Training is so important for marathon participants," Cianca said. "People need to consider their own capabilities and accept them."

To help prevent hyponatremia, Cianca recommends the following:

• Increase your intake of salt when training in hot weather. This can be done by using more table salt or by consuming foods and beverages with a higher sodium content.
  
• Don’t blindly follow training advice given for groups. Be willing to learn your own fluid needs by checking your weight before and after runs and adjusting to fluid intake accordingly.

'Winterizing' your exercise program

’Tis the season to bundle up if you are headed outside to run.

"People can continue outdoor exercise during the winter months if they take precautions," said Cianca.

While outdoor runners in moderately warm climates may have to make only minor adjustments, people working out in cold-weather states need to make equipment and clothing changes to avoid hypothermia and falls on slippery terrain.

It is still important in cold weather to be aware of your hydration needs. Weigh before and after a long run in cold weather to figure out ahead of time how the body reacts to cold weather exercise. Be sure to towel off all sweat and remove wet clothes.

Cianca suggests the following:

• Dress in layers of clothing, using long-sleeved T-shirts and jackets. As your body warms up, you can shed a layer or two and still be comfortable.
  
• Cover your head and ears. Heat easily escapes through the head if the head is not covered.
  
• Wear athletic shoes with a jagged tread to get better traction on snow-covered roads and trails.

Agony of the feet

While running is great for the heart, it can take a toll on the soles -- of your feet that is.

"Feet are one of the most neglected parts of the body when it comes to fitness," said Jane Corboy, MD, an assistant professor of family and community medicine at Baylor. "Most people don't think about taking care of their feet until they hurt. By that time, damage may have already occurred."

Using proper shoes for your exercise is the most important "step" you can take to avoid foot problems.

"If you're participating in several activities, you need more than one pair of shoes," Corboy said. "Sport-specific shoes can help prevent injuries."

Also, find shoes that are designed for the kind of feet you have – flexible or rigid, wide or narrow.

"A good running store with knowledgeable sales people can be very helpful, as can reviews in running magazines," Corboy said. "If you run every day, you might consider two pairs of the same brand, so that they can dry out completely between work-outs. Replace your shoes before they lose their shock absorbing ability - about 500 miles per pair is a good guideline."

In addition, Corboy recommends:

• Always wearing socks to help absorb the shock of exercise and keep feet dry. You may need to experiment with different materials and thickness to find the ones that work best for your feet.
  
• Clipping toenails after a bath or shower when they are softer. Pressure or prolonged pounding from shoes can irritate nails, causing them to become bruised and fall off.
  
• Rubbing or soaking feet after workouts. This helps to increase circulation and relax foot muscles. "Your feet might be sore after a workout, but they should not hurt," said Corboy.
  

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