Running alone isn't good for you...

A new study shows that running alone might cause neural degeneration in rats. But when the same rats ran in a group, there was neural generation. So running alone is bad for you. Ok, I say. Then run with a rat.

Caveat: For you long distance runners out there (myself included), we don't have to worry.

When isolated rats ran for a long time, they did see the same brain benefits as their short-term runner peers - but only when they had been running for a much longer period.