A group of humanoid robots are undergoing fierce training and systematic upgrading in preparation for a boxing contest to be held in Hangzhou, the provincial capital of Zhejiang in east China on Sunday. The boxing event is a part of a series of robot competitions jointly sponsored by China Media Group (CMG) and other institutions. One training session features two humanoid robots developed by the Hangzhou-based tech startup Unitree Robotics trading punches on a boxing ring on Tuesday. Both of them are capable of performing difficult moves like aerial spin kicks. This agility comes from the upgrades in core technologies, particularly the algorithmic breakthroughs. The research and development team at the Unitree Robotics said their boxers to participate in the contest have undergone systemic upgrades. The fighting robots are more resilient to endure blows as boxing matches are energy consuming and boxers are subject to hard punches. Then the boxing robots must be skillful, for which research and development team built specialized data bases for the robots, with collections of combat motion data for them and with the motions optimized one by one. Like their human counterparts, the boxers are also capable of automatically getting up once they fall down. Shotlist: Hangzhou City, Zhejiang Province, east China - May 20, 2025: 1. Various of humanoid robots in training for boxing contest; 2. Various of humanoid robots trading punches; 3. SOUNDBITE (Chinese) Gao Yuan, staff member, Unitree Robotics (ending with shot 4): "Compared with previous dancing performances our robots have put up before, the boxing competition involves fighting, which is the most difficult part of the project. Because in antagonism, the pressures on the machines are tremendous and there are also lots of uncertainties. It is very, very challenging for us to maintain a smooth operation while keeping the robots stable under all these uncertainties."; 4. Various of humanoid robots trading punches; 5. Humanoid robot gesturing to show confidence in winning boxing contest; FILE: Hangzhou City, Zhejiang Province, east China - Date Unknown 6. Various of humanoid robot performing martial arts. [Restriction - No access Chinese mainland]