A dry mouth, creaky knees and muscle soreness that lasts for three days.
These are signs the body wasn't meant to run a marathon, said Dr. John Senatore, chief of podiatry and a sports medicine physician at Union Memorial Hospital.
That may be affirmation for couch potatoes, but the number of marathons and the number of people willing to run 26.2 miles keep growing.
About 410,000 people finished one of about 300 U.S. marathons last year, up from 25,000 three decades earlier, according to Running USA, a group that promotes fitness and tracks trends. The median finish time for men is just over four hours and 15 minutes and for women it's four hours and 46 minutes.
During that kind of time, runners endure some degree of damage to the body. Faster may be better since the amount of time spent pounding toward the finish line contributes to the breakdown of muscles and bones, especially if a proper training regimen is not in place.
"Your body is absorbing shock," said Senatore, who has run seven marathons. "When you run for more than three hours, all that repetitive motion causes damage."
Firmness of the ground and the whims of weather also play a role in how much damage the body sustains. So do a runner's genes, training and eating habits, say local runners, doctors and nutritionists, many of whom are preparing for the Baltimore Marathon on Oct. 13.
Being ready is key to running a healthy marathon, Senatore said. "You can prepare and minimize the damage and avoid long-term injury."
Healthy people can run about eight miles on available energy; after that, the body dips into reserves. At about 22 miles, the body begins to break down, said Tyler Cymet, section head of family medicine at Sinai Hospital and an assistant professor at Johns Hopkins School of Medicine. To make it through the last 4.2 miles, training over a period of 12 to 18 weeks is necessary.
Cymet, who has run about 30 marathons, says training improves the strength of muscles, the efficiency of the heart and the health of bones and tendons.
A good regimen includes several short runs weekdays and progressively longer runs on weekends. Runners should train on ground that isn't too hard, rest regularly and replace their shoes every 400 miles.
Runners learn from each other in training groups, such as one sponsored by Jim Adams, who owns the Falls Road Running Store and has run 20 marathons.
Adams recommends novices start with shorter races, and experienced runners take breaks. He discovered this during the 2001 Baltimore Marathon, when fatigue from overtraining nearly ruined his race.
"From the starting line, I knew it was going to be a struggle," he said. "Somewhere around mile 16 the wheels came off. I had the worst second half of a race of anyone in the marathon. I learned."
Keeping the wheels on also requires water, salt and carbohydrates, says Suzanne Girard Eberle, a sports dietitian and the author of Endurance Sports Nutrition.
Running kicks up a person's heart rate, and as water and salt deplete, the heart has to pump harder to get blood and oxygen to muscles. Runners need to replace what's lost in sweat and urine.
During races, marathoners will drink both water and sports drinks such as Gatorade. The sugar in sports drinks upsets some runners' stomachs. But too much plain water can flush out salt, which keeps muscles running properly by regulating water within their cells. Too little of it can lead to hyponatremia, which causes confusion and even death.
Eberle says runners can tell if they are dehydrated or overhydrated from their urine. She said it "should be the color of lemonade, not pale like water or dark like apple juice."
Carbs are needed to replace the stores of glycogen, or energy, that are eaten up during the long runs. Runners commonly eat pasta and breads before race day and Gummi Bears and PowerBars or PowerBar Gels during a race. Without carb replacements, muscles swell and tear, slowing runners and causing soreness.
"If you run out before the finish line, it will be a very long, long day or you may not even make it to the finish line," Eberle said.
John Davis, a Baltimore photographer training for his first marathon, said his fiance, Kristen, motivated him to train for the race. He hopes to finish in less than three hours and 16 minutes, fast enough to qualify for the Boston Marathon.
To prepare, Davis has monitored what he puts in his body and when. He takes in carbs before and during runs. He hydrates carefully all day. And after a run, he eats protein to promote healing of any tiny muscle tears. After 13 years, he also quit smoking.
"I was always athletic in high school, but in college I stopped exercising and started smoking," he said. "Nov. 20 will be my third anniversary of not smoking. I'm excited about the marathon."
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