The New York Times reports that a rising number of runners are now running multiple marathons within a short period of time. 

Jordan D. Metzl, MD, primary care sports medicine physician at HSS, explains that he's seen an uptick in the number of runners attempting more than one marathon each season, at least in his own office. 

"I used to say as a blanket statement that it was a terrible idea. Now I say most people can't do it. But, some can," said Dr. Metzl.

Read the full article at NYTimes.com.