I wear braces on BOTH knees. and sometimes it's hot and I always feel like a huge dork, but they REALLY help me. I started having this weird knee thing a year and a half ago, after running down some stairs. Turns out my knees don't align properly, so it was "catching" in a weird way. Hurt and gave out alot. So I started wearing braces whenever I run, or do anything similar (I'm ok biking though), and I haven't had that problem since! And I only recently, in the last few months, started REALLY trying to build up the muscles around my knees---especially the inner muscles, these tend to be weak in women---and I think that has helped too. Don't worry--you shouldn't have to give it up completely, just give yourself a fresh start with the right shoes. And go slow at first. And do think about building up your leg muscles. It helps!