It's not as bad as it sounds. And no, I'm very skinny (except for my pot belly). You just take lots of little breaks to catch your breath and focus on keeping loose and taking big, easy strokes and use your whole body. It also helps with a D-8 with the thumb hole, so you can get two hands on it and split the load. You'll be sore when done, for sure. But I'd rather resaw for 2 hours than cut dovetails for two hours, with that short motion.
And I'm looking to start off with cheaper blades. I actually kind of like sharpening stuff, and I've seen some videos on bandsaw blade sharpening, and it looks easy enough. It's just a giant handsaw at its heart. So I'd like to try non-hardened teeth first and see how that goes. Then if that doesn't work, slowly progress through the more expensive blades until I find what I like and what works best. The way I see it, blades are consumables. So if I regret a bad purchase with one, it's not like I'm stuck with it for life. I was gonna buy a new blade one day anyway. So might as well find out what I'm upgrading from, instead of just what I'm upgrading to.