Likely stress fracture - scratching from SFM

Well, after 2 and a half weeks of persistent lateral left foot pain that keeps getting worse every time I run on it, including easy 5-6 milers, I've pretty much concluded that I've managed to give myself a stress fracture of one of the bones of my lateral left foot (likely 5th metatarsal) which will require 3-8 weeks of low to no running to recover from. It's an unfortuate turn of events, although I do expect to bounce back fairly quickly from this one, as the pain does significantly improve when I take days off.

Being a radiologist, I was able to get an x-ray of my foot, which showed no visualized fracture - unfortunately, 50% of stress fractures are radiographically occult on xray, and require an MRI to diagnose. Just when I need it though, the MRI scanner here at UCLA is down (no dedicated foot coil on the working one), and won't be up until next week, so I don't have definitive radiographic evidence for the stress fracture.

The other possibility remains a ligamentous strain, but either way, the treatment for both is identical - rest and greatly reduced weightbearing exercises, and there would be no added information from the MRI. Given my symptoms, odds are far more likely that the injury is a stress fracture, likely from the heavy combination of miles and hills I jumped back into too quickly after the SD marathon - other lateral foot injuries such as peroneal tendinitis are unlikely.

I was hoping that my foot would improve with the reduced mileage going into the minitaper for the SF marathon, but after having worsening pain after today's 11 miler, I'm deciding to opt for safer rather than sorry, especially since I don't think I'm in shape at all to run a PR at SF on Aug 3rd.

This definitely a disappointing setback for me, especially because well, "I asked for it!" by running so much after my last marathon, but I'm going to try and make the most of it and do soem serious mountain biking and fitness bike cycling to maintain my cardiovascular fitness. Depending on my schedule, I may even try and integrate some weekend swimming (I'm a lousy swimmer!) and possibly water running as well if things are taking longer than expected to heal up.

I definitely admit that I'm very surprised to be hit with this overuse injury, mainly because I've run even greater mileage than this in the past, and over a longer period of time. I was willing to push the mileage recently as well mainly because I felt that after the taper and rest weeks around the SD marathon, there was little chance for me to get an overuse injury because, well, I wasn't overusing anything! On the bright side, I suspect that I will recover fairly quickly from this injury because I haven't logged super-heavy miles on it - it's almost definitely a microfracture picked up from the buildup of long 24-milers that should respond well to plain old rest and recovery. Just goes to show that an incremental buildup is far, far better than dramatic changes in mileage, even when you've previously run high mileage successfully.

My original plan to run the California International Marathon for a BQ attempt in December is on hold for now - I'm going to re-evaluate my race schedule after everything gets more or less back in order for another go at Pfitz 18/70.