First, a bit of background: I'm 24 and have started racing. I've been training about 250-300 road miles a week for the last 3 months and things couldn't have been better. Feeling great, no problems or injuries and just got sponsored by a local store ect. Yesterday I decided to take my mountain bike out for the first time in a few months and aside from feeling rusty everything seemed ok...until I woke up this morning. My knee was stiff and about the size of a grapefruit and full of fluid. It hurts to touch it but once I get it moving the pain goes away. I didn't hit my knee or have any kind of traumatic injury but my sister in law is a doctor and said it looks and sounds like bursitis. Supposedly it can come from trauma, overuse, or an infection. From my googling it seems like trauma is the most common cause (which I didn't experience) and it seems strange that it just appeared one morning. I'm just hitting my stride in the racing season and suddenly it feels like I'm 85 years old. Has anyone else out there had this happen out of the blue? Can I keep riding through the swelling? I can't stay off the bike for weeks so that's not really an option and any advice from survivors out there would be greatly appreciated. Thanks!