I recently began a running/walking regime that lasts for 30 minutes. I think I run about half the journey and walk the other half of the journey. There are 2 very steep hills, and numerous medium hills on the journey. I tend to walk up the 2 very steep hills.
On my walk I noticed that some other people walking had very large/bulky (although doesn't look fat) looking legs. My observations of endurance athletes are that they have quite lean legs. I am weather my regime will turn my legs bulky, or if they will remain lean looking. (I would prefer if they don't become bulky, how can I prevent this?)