Why Cheetahs Are So Fast? New Study Answers

A group of scientists has discovered why some animals, like the cheetah, run faster than others. And it boils down to body size and muscles that some animals possess. The study has been carried out by a team of researchers from Imperial College London, Harvard University, the University of Queensland and the University of Sunshine Coast. It has been published in the journal Nature Communications. The team developed a model to analyse how an animal's muscles move when on land, and assessed the constraints in how fast they can run.

"The fastest animals are neither large elephants nor tiny ants, but intermediately sized, like cheetahs. Why does running speed break with the regular patterns that govern most other aspects of animal anatomy and performance?" Newsweek quoted lead author Dr David Labonte, from Imperial College London's Department of Bioengineering, as saying in a summary of the findings.

The animals that are able to reach incredible speeds do that with the help of two factors - how fast and by how far their muscles can contract, as operation the study.

The maximum speed depends on what limit these animals reach first, which is determined by their size.

The team called the first limit "kinetic energy capacity limit", which is a measure of how muscles contraction limits animal speed. The second one, called "work capacity limit", calculates how larger animals ar restrained by how far their muscles contract.

"The key to our model is understanding that maximum running speed is constrained both by how fast muscles contract, as well as by how much they can shorten during a contraction," co-author Professor Christofer Clemente, from University of the Sunshine Coast and University of Queensland, said.

"Animals about the size of a cheetah exist in a physical sweet spot at around 50kg, where these two limits coincide. These animals are consequently the fastest, reaching speeds of up to 65 miles per hour," he added.

They applied the same model on larger animals and found out it correctly predicted their maximum running speeds.