I managed to get my oldest in school right after my third child was born, so I have never had the privilege of running with a triple stroller, but if you, like some of my friends, have three kids under the age of 3, you might need one! Here are three styles that I have seen out and about that are all running-possible.
1. Baby Jogger
Double plus a "jump" seat
3. In-line strollers
There is often more than one brand offering each of these configurations, but this is a start.