Strategies to build foot muscle? Vibrams?

heykatieben

I'm training for a marathon, and the weakest links right now are my feet and knees.

For knees, I'll be working on stretching and core. What do you guys recommend for building foot muscle? I thought about walking around in my Vibrams, using them as everyday shoes, in addition to some stretches I've found online. Thoughts?

Thanks for any tips!