How do you keep a hula hoop from falling down around your ankles?

(The video is SFW despite the source.)
Someone passed me this video of a Hooters employee doing tricks with a hula hoop. It is amazing. She looks like she is genuinely having such a good time.
I had a hula hoop as a kid and, at the time, could do it forever. Her performance inspired me to try it again. I got a slightly oversize one, 40”, and went outside. Like riding a bicycle, some things you don’t forget. I could do it immediately but the hoop always eventually fell down around my ankles.

In the video she manages to make it move up and down her body, over her head, around her neck, up her legs, off her shoulder, around her elbows, etc. Take a look. How the heck is this possible? I tried slipping my arm into the hoop and it would drop every time.
Can you do it? Can you offer any tips on what I’m doing wrong -other than being the wrong sex, and probably old enough to be her grandfather?

I’ll leave this Q in Social because… well, the possibilities are endless.