“While all of the athletes’ left ventricles filled with blood earlier than average and untwisted more quickly during each heartbeat, those desirable changes were amplified in the runners. Their ventricles filled even earlier and untwisted more emphatically than the swimmers’ hearts did.” All aerobic exercise can reshape the heart. But different exercises result in different outcomes. NYT: The Heart of a Swimmer vs. the Heart of a Runner. (The heart of an internet news curator looks roughly like the heart of someone who eats bacon three meals a day.)