How strong is a grizzly bear?

Grizzly bears are every bit as grisly as they sound. Ruthless, lethal, and unrelenting, they can chase you at breakneck speed in the sense that they will speedily break your neck after they chase you. In 1910's Life-histories of Northern Animals: An Account of the Mammals of Manitoba, Volume 2, naturalist Ernest Thomas Seton marvels at the remarkable speed of the grizzly: "For 50 or 100 yards a grizzly can go as fast as a good horse, and in rough country it can go faster than any horse and keep it up indefinitely."

The naturist also describes an incident in which a wounded grizzly nipped at the heels of a man fleeing on horseback. "In my view of this," Seton said, "it will be seen how absurd it is for any man to think he can escape from a grizzly simply by running." His assessment wasn't wrong. Per Business Insider, the world's fastest sprinter, Usain Bolt, who's clearly half-man, half-lightning, has a max speed just shy of 28 miles per hour. The Best of Yellowstone Park says grizzlies can actually reach 40 miles an hour. The only thing more absurd than someone thinking they could outrun an Ursus Bolt is someone assuming they could overpower one. How strong is a grizzly? Way, way stronger than you.

The bear essentials of strength

The National Geographic Channel sought an answer to the grizzly strength question by asking Montana State University professor Doug Cairns to put bear power power to the test for a documentary. Cairns immediately pounced on the opportunity to work with apex predators, explaining, "I get some pretty weird projects. So weird has some pretty big bounds to me." Aided by a pair of graduate students, compared the tree-shaking ability of grizzlies and humans. To give the animals an incentive, the researchers smeared a measuring device with honey, jam and puréed fish heads.

Based on the data, they concluded that a bear is 2.5 to 5 times as strong as a person. Cairns surmised that if you tick off a grizzly, its bear-zerker rage will kick in, and it will be even stronger. The researchers had no interest in angering the grizzlies because nobody wants to get smashed like jam by a hulk bear.