Editor’s Note: Dr. Holly Andersen is dual board certified in Internal Medicine and Cardiology, is a Fellow of the American College of Cardiology and the American College of Sports Medicine and is an assistant professor of medicine at the Weill Cornell Medical Center. Dr. Andersen has been selected as one of America’s "Best Doctors" every year by Castle Connolly since 2001, and in 2008 was named by the Consumers’ Research Council of America as one of "America’s Top Cardiologists."

The New York City Marathon is one of the largest marathons in the world, with 37,899 finishers last year. It is a World Marathon Major, and along with the Boston and Chicago Marathons, it is one of the preeminent long-distance annual running events in the United States. It is organized by the New York Road Runners and has been run every year since 1970. It has come a long way since its initial running of 127 competitors — only 55 of whom crossed the finish line — after completing multiple loops all within Central Park. The first finisher, with a time of 2:31:38, was a firefighter named Gary Muhrcke, who plans on running again this Sunday.

The New York City Marathon was one of the first to welcome women — in 1971. Roberta Gibb ran alongside the all-male Boston Marathon in 1966 and ran again without a number in 1967. That year another woman entered the race, Kathrine Switzer, under the name K.V. Switzer. There is great footage of the race officials attempting to physically push her out of their race, but she was running with her coach and boyfriend, and together, they prevailed. Kathrine Switzer thus became the first woman to officially enter and run the Boston Marathon. She went on to win the 1974 New York City Marathon and then led the effort to make the women’s marathon an official Olympic event. This did not happen until the 1984 Olympic Games in Los Angeles.

Today, this seems hard to fathom (last year, women made up 34% of participants), but it is important that every woman running this Sunday appreciate how far we have come in such a short time. Track and field became an Olympic event for women for the first time in 1928. That year, despite a world record time by the winner, several of the women who ran the 800-meter collapsed on the field. Thereafter the Olympic organizers considered long-distance running too strenuous for women, and limited distances to a maximum distance of 200 meters. It took nearly 60 years to prove that women had the ability to run and compete in the marathon.

Marathon day in NYC is a celebration – it is uplifting – it is a special NYC holiday. But is it safe? Pheidippides, the young Greek messenger who is said to have run the first "marathon," ran from Marathon to Athens in 490 BC, delivered the news of victory over the Persians and then collapsed and died. Two weeks ago three men died at the 32nd annual Detroit Marathon and last year two of the 37,899 New York City Marathon finishers died after completing the race, the event’s first fatalities in 14 years (not counting Ryan Shay, the professional marathoner, who in 2007 died one day before the NYC marathon while competing in the U.S. Olympic trial in Central Park).

So just how safe is running the marathon?