Is running bad for knees?

I have been hearing this everywhere, is it true?

I heard this before, it doesn't make sense to me... aren't we humans built for running? I also found this on the web: " In a well-known long-term study conducted at Stanford University, researchers tracked nearly 1,000 runners (active members of a running club) and nonrunners (healthy adults who didn't have an intensive exercise regimen) for 21 years. None of the participants had arthritis when the study began, but many of them developed the condition over the next two decades. When the Stanford team tabulated the data, published in the Archives of Internal Medicine in 2008, it found that the runners' knees were no more or less healthy than the nonrunners' knees. And It didn't seem to matter how much the runners ran. "We have runners who average 200 miles a year and others who average 2,000 miles a year. Their joints are the same," says James Fries, a professor emeritus of medicine at Stanford and the leader of the research group. The study also found that runners experienced less physical disability and had a 39% lower mortality rate than the nonrunners. Read more: http://www.time.com/time/health/article/0,8599,1948208,00.html#ixzz0wZX56DD6 "

yep.. running is a very high impact exercise for your knee.. http://www.fitsugar.com/Running-Ruin-My-Knees-261188 try to read this article.. This article might be very helpful for your concern.. you can also walk fast (power walking - 3 mph - 4 mph speed) which is low impact for your knee.. If you really want to run, you need to buy a good running shoes with soft cushion for your knee.. Good luck