An international study of monkeys and folks from different walks of life shows how the human heart responds to physical activity.
A novel study that compared the hearts of African great apes, Native Central Americans, and American athletes sheds recent light on the evolution and adaptation of the human heart. But the outcomes even have a practical message.
Chimps vs. Early Humans
Chimpanzees, our closest evolutionary relatives, spend a lot of the day feeding and resting, interspersed with short bouts of climbing and fighting. This short but intense contraction creates pressure in the center chambers, leading to thicker, harder partitions. In contrast, our ancient ancestors needed to hunt and gather food to survive, which required them to walk and run long distances. As evolution progressed, early farmers relied on this same physical endurance to plow, plant, and harvest their food. As a result, the partitions of human hearts evolved to be thinner and more flexible. The heart's chambers became barely larger, and in addition they became capable of bend barely (like wringing out a towel), which allows more blood to flow out and back into the center comfortably.
The Tarahumara Indians, who live in Copper Canyon, Mexico, are certainly one of the few civilizations that remain largely untouched by Westernization. “They lead what anthropologists call a subsistence farming lifestyle that calls for walking, jogging and other movements throughout the day,” says Dr Bagesh.
“Their hearts represent how the heart has naturally evolved to function — a pure form of a human heart, if you will,” he says. But your heart also adapts throughout your life depending on what form of exercise you do – or don't do.
The heart's major pumping chamber, the left ventricle, reflects the variety of activity an individual typically does. The left ventricles of those with endurance were longer, larger, and more flexible (and subsequently capable of handle a bigger volume of blood) than average. On the opposite hand, football linemen's hearts were more adapted to short, intense workouts that mirrored their strength training. The partitions of their left ventricles were thicker and fewer elastic, allowing them to manage higher with pressure moderately than volume.
However, the group of men who didn't exercise turned out to be an important a part of the story by way of health lessons, says Dr. Bagesh. The men, all of their 20s and 30s, didn't have traditional heart disease risk aspects, comparable to hypertension. But their untrained hearts looked like monkeys with thicker and fewer elastic partitions.
“If you don't do any physical activity, you don't push as much blood through your heart and blood vessels on a daily basis. Both the heart and the blood vessels begin to stiffen,” explains Dr. Bigesh. . This creates a vicious circle: the less you progress, the less you'll have the option to do the form of exercise that keeps you healthy.
Exercise to forestall hypertension.
They say the brand new findings show that the technique of developing hypertension is ready in motion before it's first detected within the doctor's office. Unfortunately, only 20 percent of American adults get the advisable 150 minutes per week of moderate-intensity physical activity. And about one-third of adults have hypertension.
Although it's best to exercise throughout your life, it's never too late to begin. For many individuals, the transition from being sedentary to being energetic is difficult and requires real behavior change. “But the more we can help people understand the underlying reasons and implications of their choices, the better off we'll be,” says Dr. Bagish.
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