From the original posted article:

And neither he nor Parkih find these results concerning for recreational distance runners: Within two days, the runners’ body chemistries were back to normal.


From the Doheny article:

"If you want to run a marathon," he said, "run one and cross it off your bucket list." Dr. James O'Keefe, director of preventive cardiology at the Mid-American Heart Institute in Kansas City.

Been there, done that. Many people these days decide to run a marathon a month before. Um...training helps. I trained carefully for a year, ran my marathon, and crossed it off my list. They can't take it away from you!!