I'm pretty out of shape, and I've started running... why is it that after running about one mile horizontally (about 300 yards vertically - it is a steep hill that I run), the part of my body that is most uncomfortable after a few minutes of walking is my lungs? It takes a good 10 minutes until breathing deeply doesn't hurt. Each time I do run it hurts less, but I'm wondering why my legs aren't the most painful. If it matters, it is generally in the low 50s when I run.
