What did you say? No room to exercise is the reason you are unfit. Well here are 5 exercises you can divulge in that need less space. Go on, jump along that school hallway, or office corridor. Be active.
Tuck jump: Bend your knees slightly while standing and hold them in place with your hands. Jump as high as you can and land on the same posture. Repeat this as many times as you can.