
How did the human heart adapt during our evolution as a species? To explore that question, Harvard cardiologist Dr. Aaron Baggish led a unique study that compared the hearts of African great apes, Mexican farmers, and American athletes. But the findings also have a practical message.
“They reinforce the importance of regular brisk walking or jogging throughout life to stay healthy as you age,” says Dr. Baggish, director of the cardiac performance lab at Harvard-affiliated Massachusetts General Hospital. The study included great apes (gorillas and chimpanzees) and four different groups of men: inactive men, endurance runners, football linemen, and Tarahumara Indians. All underwent detailed heart function studies using ultrasounds done during different activities.
Chimps vs. early humans

Courtesy: The Leakey Foundation
Pure of heart?

“Their hearts represent how the heart has naturally evolved to function — the pure form of a human heart if you will,” he says.
But your heart also adapts over your lifetime depending on what type of exercise you do — or don’t do.
The heart’s main pumping chamber, the left ventricle, reflects the type of activity a person typically does. The left ventricles of the endurance runners were longer, larger, and more elastic than average (and therefore able to cope with large volumes of blood). The hearts of the football linemen, on the other hand, were more adapted to short, intense bouts of exercise that reflects their strength training. The walls of their left ventricles were thicker and less flexible, allowing them to cope better with pressure rather than volume.
Inactivity harms the heart

“If you don’t do any physical activity, you don’t push large amounts of blood through your heart and blood vessels on a daily basis. Both the heart and blood vessels start to stiffen,” explains Dr. Baggish. It creates a vicious circle: the less you move, the less you’ll be able to do the type of exercise that keeps you healthy.
Exercise helps prevent high blood pressure

Even though it’s better to exercise throughout your life, it’s never too late to start. For many people, changing from being sedentary to active is hard and requires a real behavioral shift. “But the more we help people understand the underlying causes and implications of their choices, the better off we are,” says Dr. Baggish.
Source: Harvard Health Blog.
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