All my shoes are a size 11. 10.5 is always too small but I find some shoes at 11 are roomy. I bought the 45 and they fit perfectly. You can run in them, but so far I've only used them for indoor workouts. I don't know how long you want to walk on unpaved surfaces, so I wouldn't recommend anything other than gravel. They are a bit slippery on my smooth concrete basement floor. I like Velcro. I can put these shoes on and take them off very quickly. They are comfortable and go well with the cleats on my Shimano platform/SPD pedals.