A new study on the power of chimpanzees has challenged a century of assumptions on the super-strength of our primate cousins, finding their muscular performance is actually about 1.5 times greater than ours.

Our results show that chimpanzee muscle exceeds human muscle in maximum dynamic force and power output by ∼1.35 times. This is primarily due to the chimpanzee’s higher fast-twitch fiber content, rather than exceptional maximum isometric force or maximum shortening velocities.

Chimpanzees do have stronger muscles than us – but they are not nearly as powerful as many people think. “There’s this idea out there that chimpanzees are superhuman strong,” says Matthew...

The researchers found that whereas human muscle contains, on average, about 70% slow-twitch fibers and 30% fast-twitch fibers, chimpanzee muscle is about 33% slow-twitch fibers and 66% fast-twitch fibers.

Here, we described a detailed three-dimensional (3D) musculoskeletal model of the chimpanzee pelvis and hind limb. The model includes geometric representations of bones and joints, as well as 35 muscle–tendon units that were represented using 44 Hill-type muscle models.