'After age 50, pushing too hard is probably not good for one's heart or longevity...'

Well, I haven't been running lately, so I guess there's an upside to the latest science. At the Wall Street Journal, "One Running Shoe in the Grave: New Studies on Older Endurance Athletes Suggest the Fittest Reap Few Health Benefits." And from the report:
The most vocal proponent of cutting back for cardiac reasons is Dr. [James ] O’Keefe, a 56-year-old cardiologist and former elite athlete. From 1999 to 2004, he won outright the largest sprint distance triathlon in Kansas City, a testament not only to his athletic abilities but also to hours and hours of early- and late-hour training.

But a sense that this regimen was aging him prematurely, coupled with the mounting awareness of cardiac issues in extreme endurance athletes, prompted Dr. O’Keefe to slash his running to below 20 miles a week, never faster than eight minutes a mile.

Asked if he ever runs a 5-kilometer race for time, he said, “Not for the past three years. After age 50, pushing too hard is probably not good for one’s heart or longevity.”

Meanwhile, Dr. O’Keefe’s fellow author on the upcoming Heart paper, Carl Lavie, continues racing at speeds slightly above what their editorial recommends. “I did a turkey day five-mile race in 38 minutes,” said Dr. Lavie, a cardiologist at the John Ochsner Heart and Vascular Institute in New Orleans. “I train slower than I race, and when I race I know the risks. That’s all we’re trying to do: Let people know the risks and make up their own minds.”
More at the link (via Instapundit).