This activity shall be under professional supervision. At the minimum, one competent, experienced gentleman or two people would be preferred depending on the size of the circle.  Probably…we had about 17 people in our circle.  One guy did it but we were in shape. It became hard to hold everyone up once.  The gentleman helped me right the ship.

https://johnrubens.wordpress.com/2018/05/08/flotus-competes-in-time-http-blogosphere45-blogspot-com-2018-05-hyperventilate-and-hypnotize-with-html