How a Marathon Works

The Health Risks of the Marathon

Ryan Shay (#8) leads the pack in the 10,000 meter run during the U.S. Olympic team track
Jamie Squire/Getty Images

Being able to run 26.2 miles means you're in optimal health, right? Not exactly. We've already identified some of the benefits of long-distance, endurance running, but now we'll delve into the darker side of the marathon.

Marathoners who die training or on the race course usually make headlines because these tragedies seem so unusual -- who could be in better health and less likely to die than a runner? At the age of 52, Jim Fixx, a celebrated runner who wrote "The Complete Book of Running," died in 1984 of arteriosclerosis [source: New York Times]. In this condition, the arteries' walls become clogged and thickened, causing less blood to flow through them. In 2007, 28-year-old Ryan Shay died while competing in the U.S. Olympic marathon trials. His death was attributed to an irregular heartbeat [source: AP].

It's pretty obvious that running affects the heart, but did you know that running can actually increase the size of the heart? Hearts can enlarge when an athlete is engaged in serious physical training. The body compensates for the increased amount of blood it needs to pump throughout the body by increasing the size of the organ where it originates. Enlarged hearts can lead to arrhythmia, or irregular heartbeat, which can, in turn, lead to heart failure. Diagnosis of this condition is tricky -- it's difficult to tell whether an athlete's enlarged heart and its thicker walls are exercise-induced or a sign of hereditary disease [source: Allison].

Another rare but potentially fatal condition is hyponatremia. This occurs when runners drink too much water while racing. Your body loses sodium when you sweat, and drinking too much water depletes your sodium even further because you release it through urination. If you take in too much fluid, your muscles can't coordinate the proper electrical transmissions with your heart, resulting in a sudden cardiac arrest (SCA) [source: Galloway interview]. To avoid hyponatremia, it's best to limit your fluid intake to no more than 13 to 27 ounces per hour [source: Galloway interview].

Some marathoners assume that their fitness level absolves them from health problems. This simply isn't the case. Medical examinations can pinpoint the kinds of heart irregularities and risk factors that kill and injure runners. But there are ways to reduce your risk factors, too. Don't assume that you can eat or drink whatever you want because running will burn off the calories -- diets rich in saturated fat can lead to heart problems further down the road.

In addition to these life-threatening aspects of the sport, there are other sports injuries to beware of. Most of these are overuse or overtraining injuries that can be prevented by tapering your training -- that is, resting properly and cutting back on your mileage. These are a few of the most common infirmities:

  • muscle stiffness and soreness
  • pulled, torn, strained or sprained muscles
  • tendinitis (inflammation in the tendons)
  • shin splints (tenderness in front lower leg)
  • heel spurs (calcium deposits in the heels)
  • diarrhea, nausea, fatigue and mood swings

[source: Bloch]

While you should approach the sport with caution, you should also have fun running. Specialized training programs can help you achieve this goal. Running guru Jeff Galloway says his biggest running accomplishment is staying injury-free for 29 years. His philosophy? "I am personally against injuries, death and puking" [source: Galloway interview].

For more information on marathons and related topics, visit the links below.

Related Links

More Great Links


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  • Altman, Lawrence K., M.D. "The Doctor's World; Jim Fixx: The Enigma of Heart Disease." New York Times. 24 July 1984. 19 March 2008. 9E07E4DB1E39F937A15754C0A962948260
  • "Autopsy: Heart Problems Killed Ryan Shay." AP. 18 March 2008. 19 March 2008. VG4DAO0
  • BBC Hot Topics: Marathon. BBC. 18 November 2004. 28 February 2008.
  • Big Peach Running Company. "The Fit Process." 2008. 19 March 2008.
  • Bloch, Gordon Bakoulis. "How to Train for and Run Your Best Marathon." Simon & Schuster. 1993.
  • Bohls, Kirk. "Kenyans run in marathons for survival." Austin American-Statesman. 17 February 2008. 28 February 2008.
  • Boston Athletic Association. "History of the Boston Marathon." 28 February 2008.
  • Burfoot, Amby. "The Less-Is-More Marathon Plan." Runner's World. 2006. 28 February 2008.,7120,s6-238-244-255-8257-0,00.html
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  • Galloway, Jeff. Personal interview conducted by Candace Gibson. 7 February 2008.
  • Hatfield, Heather. "Runner's High: Is It for Real?" WebMD. 17 October 2006. 28 February 2008.
  • "History of the ING New York City Marathon." ING New York City Marathon. 28 February 2008.
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  • Lovett, Charlie. "Olympic Marathon." Excerpt: "The Games of the I Olympiad: Athens, 1896." Marathon 1997. 7 February 2008.
  • Mihoces, Gary. "Marathon's 26.2-mile run tests body, mind." USA Today. 20 February 2003. 28 February 2008.
  • O'Connor, Fed. "RFID helps the Boston Marathon run." InfoWorld. 9 April 2007. 28 February 2008.
  • "The Marathon Effect: Tips for Spectators Inspired by the Race." Boston University. 11 April 2005. 28 February 2008.
  • "Study links marijuana buzz to 'runner's high.'" 2004. 28 February 2008.
  • Young, Stephanie. "Way to Run!" Fitness Magazine. May 2008.