As 11 / 12 year olds me and the gels went through a phase of hyperventilating, then being squeezed hard from behind until collapsing in a heap.
No idea where we got the idea from or why we did it, except it was exciting and we knew it had to be kept secret !
Actually sounds pretty tame compared with todays shenannigans, but felt very dangerous and bad to us at the time.