China’s humanoid robot wins marathon with liquid cooling

A team of engineers in China developed the first humanoid robot to finish a full marathon without stopping. The achievement demonstrated more than endurance. The real advance came from the robot’s ability to control its temperature during the run. Most humanoid robots overheat after 30 minutes of continuous movement. The robot avoided this issue with a custom liquid-cooling system built into its frame.

The cooling system pumps a water-glycol mix through channels in the robot’s legs and torso, drawing heat from the joints and releasing it via a radiator on its back. Sensors track temperature in real time, adjusting flow rates to prevent overheating.

Other companies are also pursuing humanoid endurance. Boston Trends’ Atlas performs backflips and short sprints but lacks long-haul capability. Tesla’s Optimus shows potential in factories, though its battery restricts active movement to about an hour.

The marathon route included real-world conditions—uneven sidewalks, crowds, and a sudden rainstorm on the second day. The robot’s vision system, using depth-sensing cameras and a lightweight AI model, allowed it to dodge obstacles without slowing. It maintained an average speed of 0.8 km/h, matching a brisk walking pace.

Some observers dismissed the event as a publicity stunt. “Running in a straight line for 54 hours doesn’t prove real-world utility,” said Dr. Elena Vasquez, a robotics professor at MIT. “Still, it confirms that thermal management is now a manageable problem, which matters.”

The technology behind the robot could extend beyond robotics. The liquid-cooling design might improve high-performance computing, electric vehicles, or space exploration, where heat dissipation poses major challenges.

The marathon wasn’t perfect. The robot stumbled twice—once over a loose paving stone and again when a spectator stepped into its path. Each time, it recovered without falling, using a balance algorithm that adjusts its center of gravity instantly. The team noted wear on its knees after the run, indicating durability remains an issue.

Unitree intends to release a commercial version of the robot later this year for logistics and manufacturing. The company hasn’t revealed pricing, but analysts expect a cost between $90,000 and $120,000—far less than comparable industrial robots.

Choosing the right logistics partner could soon involve robots handling warehouse tasks.

For now, the robot holds the record as the only humanoid robot to finish a marathon. The next goal is a 100-kilometer ultramarathon next spring.

The push to create practical humanoid robots continues. The robot’s marathon proved machines are inching closer to human-like reliability.