A team of Japanese researchers has built two humanoid robots that can do pushups, situps and stretches just like their human creators. One can even sweat, releasing heat generated by the physical activity.

In the latest issue of the U.S. journal Science Robotics released this week, Yuki Asano and colleagues from the graduate school of information science and technology at the University of Tokyo explain how the two robots — named Kenshiro and Kengoro — were designed to mimic human systems, including muscle and bone movements.

Kenshiro, developed between 2011 and 2014, and Kengoro, developed from 2015 onward, aim to mimic the body proportions, skeletal structure, muscle arrangement and joint performance of average humans.

Kengoro, which is 167 cm tall and weighs 56.5 kg, is also equipped with five-fingered hands and feet that can naturally touch the ground, and can even artificially perspire — a feature that allows it to release motor heat.

“A sponge-like metal material, created using a 3-D printer, is used in part of the skeletal structure,” Asano told The Japan Times in an email. “We have designed a cooling system that makes water seep through the material and evaporate.”

He said this has allowed Kengoro to continue pushups for several minutes while keeping the motors from overheating.

Asano said he hopes the technology will lead to a better understanding of the human body and brain.

“Our sensor data can point to which muscles contribute to specific physical activities,” Asano said. “We hope such data can be applied in the fields of medicine or athletics, where insight gained can be utilized for rehabilitation and training.”

The aluminum bodies, powered by numerous motors, feature flexibility not achieved in earlier versions of humanoid robots, according to the researchers.

A unique multijointed spine and muscles are made up of a combination of electrical motors, mechanical parts, wires and sensors carefully linked together.