that is someone HANGING UPSIDE DOWN from a pole, using only their INNER THIGHS to keep them from crashing head-first onto the hardwood floor beneath them. you may have also noticed my personal thoughts on the matter. some of you are probably thinking "yeah, but thighs are a pretty strong muscle group! that's probably not as hard as you're making it sound."
well. i'd also like to remind those people that most of our inner thighs aren't out and about in public all that often, which means we have soft little tender baby skin there. and holding up your entire body weight using, in large part, the friction of that skin pulling against a pole...? NOT AWESOME. i'll, uh, leave you with that image now. you're welcome.