Something called "hallway swimming" is taking off on YouTube.  Last week, a kid in Canada posted a video of himself doing it, and now a bunch of other people have too.

 

 

 

 

 

Basically, you find a hallway with a freshly buffed floor, and walls that aren't too far apart.  Then you lie down, and pretend to 'swim' back and forth across the hall by kicking off the walls, the way you would if you were doing laps in a pool.

 

 

 

 

It sounds confusing, so you kind of have to see it to understand.