My name is Katie, and I’m planning on running across the U.S. from Boston to San Diego starting this March! I’m 23 and have been an avid runner since high school. I train on my own now and am deciding whether to run 9-12 miles a day or kick it up to an average of 20 miles a day. I’d like to understand what the effects of the two choices would be. Under the 20 mile plan, I’d run long, slow distance with some walking. The 9-12 mile plan would be the same with less walking. If I’m going slow, would covering the extra 10 miles a day be harmful to my body? What is the risk of injury and long term health/bone problems if I did 8 months of 100 mile weeks compared to 12 months of 60 mile weeks?