I have to agree with Petite. Film acting is hard of course, but even film I feel you do it for a few months and then many actors choose to just take a break and whatever. But TV acting feels INSANE to me, working 16 hour shifts for a single-camera series is just...wow, and what's sad is that I believe that is more or less the average. TV actors do shoot scenes at 4am, whether they have to pretend they are having the most exciting moment or their laughs, the most hilarious moment of their lives, the most erotic one, etc. I mean, what is that?
Of course doing Broadway is insane as well, but I don't think you can say one is hardest than the other. I do believe (and it's not like I've ever done TV/film work so how would I know?) that Broadway has to be more rewarding--in terms of your viewers-- simply because of the live audience factor.
"Some people can thrive and bloom living life in a living room, that's perfect for some people of one hundred and five. But I at least gotta try, when I think of all the sights that I gotta see, all the places I gotta play, all the things that I gotta be at"