I saw this online today...
I've got one like that! My only defense at this point is to push her off...while laughing. She thinks it's a game, and the paws go flailing - stepping on my stomach, chest, neck, and head.
And this morning, I did eight push-ups with a stuffed, squeaky dinosaur toy sitting on my back. Rigby brought it to me and set it on the flat of my back. A gift!
About half the time, she waits patiently on her bed or by the back door looking out the window when I work out. The other times she thinks me being down on the floor means it's time for some fun. It's very endearing, but a pain nonetheless.