Why is the cheetah the fastest animal on the planet?

Scientists discovered that cheetahs can run faster than 100 km/h thanks to their appropriate body weight .

Fast running animals like cheetahs are usually medium sized. A group of international researchers from Imperial College London, Harvard University, University of Queensland and University of the Sunshine Coast investigated the cause and published their findings in the journal Nature Communications, Newsweek reported on March 13.

The cheetah is the fastest running animal on the planet. (Photo: Mateo Juric).

Dr. David Labonte from the Department of Bioengineering at Imperial College London and his colleagues found that there are two limits to how fast animals can run: how fast their muscles can contract and how quickly their muscles can contract. How much? At the first limit, called the 'momentum capacity limit,' the muscles of smaller animals are affected by how quickly they contract. With the second limit called "activity limit" , large animals are limited by how much their muscles contract.

According to Professor Christofer Clemente from the University of the Sunshine Coast and the University of Queensland, cheetah-sized animals exist at a physical sweet spot of 50kg, where the two limits intersect. Therefore, they are the fastest species, able to reach speeds of up to 105km/h.

When testing the model's accuracy, the team found that it correctly predicted the maximum running speed of many different animals including large mammals, birds and lizards. Not only does the model answer the question of how one species runs faster than another, it also sheds light on muscle evolution and provides clues as to why there are large differences between animal groups. For example, why are large reptiles like crocodiles slower than mammals?

Taylor Dick, a study co-author from the University of Queensland, said that's because limb muscles make up a smaller percentage of the reptile's body. They need to reach their limits of activity with a smaller body weight, which means they need to be small to move quickly. For large animals like rhinos and elephants, running is like lifting a giant barbell because their muscles are relatively weak and require more strength to overcome gravity. As a result, animals move slower as they become larger.

Research also shows that the heaviest animal alive today on land is the African elephant with a weight of 6.6 tons.