Python Hearts Pump Up

A Burmese python can increase the size of its heart by 40 percent in just two days.

To get a workout, most people have to do something athletic, like running, swimming, or biking. When Burmese pythons want to build up their hearts, all they have to do is eat. So say scientists from the University of California, Irvine.

After eating, this six-foot-long Burmese python will remodel its internal organs temporarily to aid digestion.

Bryan C. Rourke

Burmese pythons are among the couch potatoes of the snake world, but without the snack habit. They just sit around for weeks or even months and wait for a mega-meal to walk by. Large pythons regularly eat pigs and other animals that are as big as they are.

A python’s overall body chemistry, or metabolism, can get going up to 40 times as fast as normal after it stuffs its face. The metabolism stays extra-active for 14 full days—the time it takes the snake to digest its meal. “It’s like running a marathon but doing it for 2 weeks,” says Stephen Secor of the University of Alabama at Tuscaloosa.

About 10 years ago, researchers discovered that a python’s heart and organs expand right after the creature devours its food and later go back to their normal size. Recently, the California scientists took another look at the python’s heart.

First, they measured snake hearts before and after the animals ate. After comparing parts of the heart containing their natural fluids to dried-out versions, the scientists found that the ratio between the two preparations stayed the same. That means that a digesting python’s heart gets bigger by adding muscle, not by filling with fluid.

The scientists also found that the hearts of digesting snakes contain large amounts of a chemical compound that cells use to make muscle fibers. Hungry snakes don’t have nearly as much of this compound.

Human hearts don’t show the drastic changes in size that snake hearts do. Our eating habits are far too regular. Still, scientists predict that studying the python will help them understand how all hearts grow. The research might also eventually lead to more effective training for athletes.—E. Sohn

Going Deeper:

Milius, Susan. 2005. Shortcut to big heart: Pythons build cardiac muscle in record time. Science News 167(March 5):149. Available at .

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