The gallant crew of the spaceship Voyager works out with invisible weights, which seems to involve a lot of heaving chests and gasping, in this bizarre scene from Disney's Earth Star Voyager.
And here's another crazy clip of the show's space workout, with some plot thickening along with all the sweat and workout-miming. (It turns out the fitness instructor is actually the guy who's been pushing the crew out the airlocks one by one, and it's part of a huge conspiracy to do something or other, in collaboration with some mohawked gladiator dudes and a skanky cyborg.)
Could we have discovered the reason why Disney never put this miniseries out on DVD?