"...after the age of 25...", well then! I got another few years of harmless sitting to go!
No but, this isn't really news. Sure, of course it requires studies to be done in order to verify it, but a pinch of logic is enough to tell you that sitting on your arse all day is bad for you when done excessively.
..perhaps I should stop complaining about the stairs in my home. I have about 13 steps down & 13 steps up whenever I'm going to the kitchen or living room .. which I do. Frequently. Can't get enough of that kitchen.