All kidding aside, I was in a very similar NASA experiment a long time ago.
It was part of Skylab, our first space station back in the 1970s.
To try to mimic the loss of muscle tone experienced by the astronauts due to microgravity, volunteer such as myself were restricted to bed for 48 hours. We were not allowed to even move around in bed, just had to lie still on our backs.
The scientists involved were great and tried to help us by changing channels on the TV to give us a bit of entertainment. They would also talk to us and made an effort to keep us from going crazy.
Periodically, like every couple of hours, they would take readings of our vital signs. One key tool was an experimental plethysmograph, to monitor blood flow in muscles IIRC.
Before the 48 hour stint, I had to eat a special "low bulk" diet to ensure there was no urgent need to poop during the experiment.
Doesn't sound all that bad, but I can assure you it was pure torture. You got so restless and the urge to wiggle around was so strong that as time went by I was ready to scream. In fact, I was one of the few volunteers who made it nearly the whole 48 hours.