As seen on http://cancersensibility.org/
Way back in 1996, the US Surgeon General issued an important report on physical activity and warned us that regardless of our age, we are just not active enough. Since then, you may have been scratching your head, wondering just how much activity would make the Surgeon General happy.
 That number is 10,000 [...]

OK, a bit of a harsh title, but read on to see my REAL intent:
http://ctchallenge.org/Page/3520/Are-You-a-Fitness-Loser.html