Wow. Here is an interesting study that was pointed out to me by Ed Sim on his BeyondVC blog.

QUOTE:

A survey of 336 entrepreneurs found those who regularly run reported better personal satisfaction, independence and autonomy than their non-running or weight-training counterparts. The study also found that companies managed by runners report better sales results than firms directed by non-runners.
[…]
The results indicate that running is positively related to all three outcome variables while weight training is positively related to external and internal rewards but not sales.

UNQUOTE: