One obstacle Kerri and I have both found is when asking a Korean about help with directions, distances and other useful information, we are told the same answer, "Take a bus." It seems most people are worried about how tired we will get! Which is sweet, but not ideal.
I've been building my fitness over the last few months also. Getting up at 6am(!) to swim three times a week and going for long walks. It's still going to be a struggle, but a exciting one!