Galveston County Daily News (Internet / Print) 01/19/06 Most of us have an understanding of the discipline and long hours of training, and the enormous mental effort it must take to run a 26.2-mile marathon.  So try and imagine the incredible willpower it must take to run 100 miles almost nonstop for 30 hours straight, and the joy runners such as Kim Sergeant must feel after finishing one of these long, difficult races. Sergeant, 47, resides in Galveston and is director of clinical pharmacology at the University of Texas Medical Branch. She has master degrees in information science and clinical pharmacology from the University of Pittsburgh and has been a licensed pharmacist since 1981.