Does Marathon Running Prevent Heart Disease?

Back in the 1970s Dr. Ken Cooper's book on "Aerobics" suggested the key to preventing heart disease was regular aerobic exercise. Long distance running  became increasingly popular in part because of its many purported health benefits. Perhaps the lead marathon running  guru back then was Jim Fixx who wrote the best-selling book on running titled "The Complete Book of Running". The death of Fixx a...