Sheehan began writing a weekly column in the local newspaper and continued to write the column for twenty five years. Many of these years were served as the medical editor for "Runner's World" magazine. (He had been introduced to Joe Henderson by Hal Higdon during the 1968 Olympics. Henderson later recruited him as medical editor for Runner's World.) He continued to write for Runner's World after the magazine was purchased by Rodale Press. He wrote eight books and lectured around the world.