So I stuffed my backpack to its brim with books until I could fit no more and then I did pull ups with it.
Oh boy this is easy I said to myself.
Then I weighted it. Motherfu-
Only 15 pounds what a joke.
It looks like I’m going to have to buy weights unless I can figure something clever out.

Oh wait I think I found a solution in my backyard. (Thanks to Laurina Koerner for the idea to use bricks)