Energy Wasted in Electromagnetic Motor Actuator Vs Human Muscle Actuation

I would like to know if the energy utilized by a robotic arm is greater compared to the energy utilized by human arm. Robotic arm is essentially servo motors that use electromagnetic field to create motion while human muscles use muscle fiber compression/elongation and to activate motion. So is there any comparison study that points out the efficiency for both?

It does appear that human muscles uses far less energy as the amount of cooling required for human to move say 1km is not significant (body temperature rarely reaches 38 deg C, while motors do tend to heat up to 40 deg C for mild load. Now this is probably oversimplification hence I would like to know if there is some analysis that concludes or indicates the efficiency of the human muscle vs motor for same or similar actuation?

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Based on the comments, I would like to know if there is a comparison for both based on unit energy, keeping the mass of both the actuators same.