Amazing news reported in New York Times that exercise in young rats creates more contractile heart cells that remain for their entire lives. We don’t know if this will have a similar reflection in human heart health but it is critical that we make sure our children exercise. The New York Times reports “The hearts of the childhood runners, though, teemed with about 20 million additional cardiomyocytes — the type of heart cell that contracts — compared with the hearts of the sedentary rats of the same age.”