My friend has played the faint game about 7 times today.however he didnt do it where you choke yourselft, he hyperventilated then blew hard onto his thumb. He is a very athletic and intelligent person, and i dont want him to get hurt. I am wondering if it will still kill brain cells if it is done in this manner.i dont know if it should or not since i read up on it and this way it makes the co2 be cleared out of your blood really fast and then something else happens. could anyone please explain why this way causes the person to faint and if it will damage brain cells? please tell me how to make him stop if it does.... i really care about him ( in a non-homosexual way) and dont want him to get hurt or anything like that- we have a duet violin and cello together next month.