Is there such a thing as working out too hard?

Posted at 2:20 AM, Dec 01, 2012
and last updated 2012-12-01 02:20:05-05

(CBS News) – Vigorous exercise is good for you, but some cardiologists say too much could be a bad thing.

A warning published in the journal Heart says it’s best to limit vigorous exercise to 30 to 50 minutes a day.

Researchers say the idea that more high intensity workouts is beneficial is a myth and that evidence shows it can do more harm than good to your heart.