Bodybuilders in space might seem like a pipe dream to you but there is one reason why it might happen. Astronauts in significantly longer trips than to the Moon (like to Mars) will need to exercise at least 4 hours a day.
The reason for this is because people lose bone density when they are under weightlessness. Exercise slows this progression. More exercise means it is slowed even more. Bodybuilders are known for their exercise tolerance. So maybe they will be the first ones sent to Mars.
Otherwise, the first words we hear from Mars could be, “That’s one small step for a AIEEE! man , one broken leg for a man!”
Bodybuilders may be a natural, but they have this nasty habit of preferring to exercise with free weights. “No,” their commanders will tell them. “You must exercise with resistance bands.”
The argument will go on for a long time. Then the commanders will say, “Absolutely not. Every kilogram of mass means it’s more expensive and harder to lift the rocket.”
“Are you saying you want scrawny bodybuilders, too? That’s it. I’m out.”
It would seem that the bodybuilders to Mars program is over. But the commander will have one more trick up his sleeve.
“Have you thought about doing a space walk while en route? In it you can touch the outside of the rocket and say you are going to bench press the whole thing without the bench. Just move your arms like you are bench pressing the rocket and have the selfie camera filming it like you are at rest and the rocket moves.”
“But everyone will know it’s a trick.”
“And you can say it’s a law of physics. Each time you pressed the rocket it moved a tiny bit. It’s all relative you might say. They might even think you know something about relativity.”
“I know. I’ll say work out smarter, not harder. I’ll get my own chain of gyms and become a national icon.”
With that settled they only had to fiddle with the details.
But no matter how hard they fiddled, the bodybuilder refused any exercise except free weights.
And that’s why there will be no bodybuilders in space.