I recently started running outside. For the first few times I did it, I didn't have any problems. Then my knee started hurting so I started wearing a brace on it. Well I ran for three days in a row and then I got sick, so I had to take some time off from running. Well during the time off, both of my knees started hurting and when I tried to run agian, I couldn't because they both hurt. Any idea what would cause this?