I started doing spin class three weeks ago and have been going 2-3 times a week. After the first few times I noticed a slight pain in my left knee. I didn't think much of it because I haven't been very active the past few months and figured I was just out of shape. My right leg is also my strong leg so I figured my left leg just has some catching up to do. It would never hurt during the class only after and then would go away until after the next class. I went to one today and pushed myself harder than usual and midway through my left knee started hurting so I took it easy for the rest of the class and the pain was pretty much gone by the end of it. Now I'm sitting here two hours after the class with an ice pack on my knee and can't walk without spikes of pain shooting through my knee every time I take a step. I had never done a spin class until three weeks ago and haven't ridden regularly because I didn't own one until just this week. Does anyone know what might be causing this and how I can fix it? I spoke to the spin class instructor after the class today and she said it was likely because I did not have the bike set up correctly and told me to raise the seat and set it back farther so that my knee isn't coming in front of my foot during the pedal motion. I'm going to try it but I figured I would be having the same problem in my right knee if that was the case. My right knee is perfectly fine. Thanks!