Those fault lines are unpredictable.
I also like the guy who swings wildly on his reps to show off. Specifically, that structure w/ the arm sling things hanging form the top, where you put your upper arms through them and bring your legs upwards to hit your abs.
This older, chubby guy was talking to this younger, chubby guy on how many reps they cna do.
Younger Guy: Man, I can only do about 5 at a time of these.
Older: Really? These are really easy for me.
The younger guy did 5-6 slow, good form, reps.
The older guy got on and started swinging back and forth as hard as he could to build up momentum. It wa slike being on a swing and he was building up for the jump off. the back of the structure would come off the ground by about half an inch every rep.
After his 15 rep set, he gave the "see, I'm the shit" look to the younger guy, the younger guy jsut smiled. Does anyone know the thing I'm talking about?