If you can stand up, you can work out.
As anyone who has ever lived in a one-room college dorm will tell you, sometimes you need to get a little creative with your exercise. If all you have a single 6×6 rectangle between two beds, that obviously limits your options a bit. But as long as you’ve got some floor, some wall, and a pair of legs, you’re not out of the game just yet.
Here’s an easy example: the T push-up, wall variation. Stand arm’s length away from the wall, then place your hands on it. Draw yourself toward the wall, then push yourself back without falling over. While not quite as intensive as a regular push-up, you make up the difference with more reps and stalls between reps.
If you’ve got the floor space, try butt-kickers. Silly name aside, it’s great cardio. Just run in place, but instead of just stepping normally, try to reach your heels back as close to your butt as you can. Try not to actually kick your butt, though, because A: you’ll probably over-extend yourself, and B: it’ll probably hurt. A few sets of thirty-second sprints will get those legs pumping.
Workout equipment can still be used in a confined space. If you’ve got a resistance band, you can do chest presses. Just lock one end of the band to a door or sturdy hook, and stretch out the other end with one of your hands. Make sure to really engage those core muscles! 15 pulls with each hand will do you fine.