I'm 25 and run 65-80 miles a week. Oftentimes I experience lower back pain at night. The pain tends to be on either side of my tail bone and is exacerbated by lifting my legs or rolling over in bed. It isn't the most unbearable pain, but it worries me because I feel like I'm too young for back pain to be a regular occurrence. Has this happened to anyone else? What did you do to help it?