All I can say is, if you get the right size and weight of hoop, you'll most likely be able to keep it up. Bigger really is better when you first start hooping; it's easier to keep a large hoop up. Counterintuitive, I know, but it's true.
And if you injure yourself, you'll recover. I should know - I tore a calf muscle about four months into my hoop journey, and although it took me five weeks to walk without a limp, it didn't make me drop hooping, I'm telling you - it's one of the most fun ways you can get yourself moving. Add your favorite uptempo music, and you'll get a great cardio workout. A strength workout too, especially if you use a heavier hoop. Just keep some arnica gel or cream on hand, because bruises come with the territory when you're starting out or when you're trying to get a new move down.
Anyway, I hope you'll give it a whirl. It's definitely a great way to get some exercise; you can burn 7 calories or more a minute, depending on how much intensity you put into it. I've heard of studies where people doing really hardcore, high-intensity hooping have burned over 600 calories in an hour.
If you gotta jump through hoops, you may as well make it work for you...