Parkour: do you do it?

Poll: do you do parkour

yes
100.00%
2
no
0%
0
i know people who do
0%
0
Total: 100% 2 vote(s)
Okay so do you do parkour? I have been doing it for around a year, I'm not that good at it due to my knees probably needing surgery. I keep putting it off 'cause of family stuff but I can't run more than three blocks without my knees giving out.
so your thoughts on parkour are? reasons you do or dont do it?
http://worldbeyblade.org/Thread-Parkour