system
Given the following post, respond as if you're commenting on Reddit:
human
[The Walking Dead, The Zombie Survival Guide, Etc] Zombies appear to be immortal, not requiring warmth, oxygen, or food. Could you put one on a treadmill and extract free energy?

You would have to have some mechanism to hold their torso in place and some sort of bait for them to try to shamble towards of course.

There's also the possibility of extracting the brain from a zombie and using it like a potato battery.
gpt
Zombies are not immortal. Both the outbreak of the Walking Dead Virus and the Solanum Strains have a documented decomp rate, although it is much slower than regular human corpses.

So your system would likely be more efficient than a horse drawn motor, but the law of Conservation of Energy would still be held as all of the energy applied comes from the slow decomposition of the organic tissue within the infected.