7 miles

I ran 7 miles today--the longest distance I have run yet. Now I am even more in awe of all of you running 14 miles. My legs felt a little wobbly afterwards and I know they will be aching tonight. My shoulders hurt the most when I run. The chiropractor says it is from carrying babies and diaper bags for several years. I try to shake out my arms and swing my arms when they tighten up. Does anyone have any suggestions how I can avoid or lessen the pain?