Studies have repeatedly shown that running is NOT hard on the knees. Instead, the risk of osteoarthritis (knee problelms) is more associated with aging. http:/

Studies have repeatedly shown that running is NOT hard on the knees. Instead, the risk of osteoarthritis (knee problelms) is more associated with aging. http://europepmc.org/abstract/MED/8478853/reload=0;jsessionid=nA7UGrTxcNrLd9GZn3pC.2 http://europepmc.org/abstract/MED/8478853/reload=0;jsessioni... http://jama.jamanetwork.com/article.aspx?articleid=403118 http://jama.jamanetwork.com/article.aspx?articleid=403118 http://ajs.sagepub.com/content/18/4/379.short http://ajs.sagepub.com/content/18/4/379.short And a less scientific article on the topic: http://well.blogs.nytimes.com/2013/09/25/why-runners-dont-get-knee-arthritis http://well.blogs.nytimes.com/2013/09/25/why-runners-dont-ge... Plus, I don't think that's a particularly cogent argument to make. You can say that about anything, pretty much. If you increase gas prices, then a percentage of those drivers will start biking/walking/running. Better not increase gas prices... Or you can replace "gas prices" with anything that affects mode of travel: taxes, congestion, surplus of bike frames, health fads, etc.