That seems to be the conclusion of a study to be published in the British journal Heart next month. The press release published by the WSJ spins it differently though, stating that running a lot later in life eliminates the mortality benefits. With the tone they take it's hard not to be tricked into thinking the evidence being presented is that running hurts you, but nowhere (in the summary piece at least) is this claim made.
It's a strange article to say the least. "Danger! Danger! Doing activity X that you enjoy doesn't harm you!" doesn't seem to be a crucial finding. To quote Kenneth Cooper in the article: "If you are running more than 15 miles a week, you are doing it for some reason other than [physical] health."' Agreed! (Qualifier mine.)
15 hours ago