I doubt if anybody on this forum will read anything they didn't already know -- but the BBC newspaper published a nice little article on cycling and its health benefits...

Except for a couple jabs like
"...cycling has middle-aged men in lycra..."
or
"But he warned: "You might look a bit silly in lycra."
it's not bad

The web address for the article is:
http://www.bbc.co.uk/news/health-18954012