Wow OK I have to respond to refute Lillym's response. Her perception of ADHD is, well, certainly not universal. While many children with ADHD can hyperfocus on activites that they enjoy (getting reaaaallllyyyy into legos or drawing a picture or playing a game), I have never had my kids or their friends hyperfocus on things that are off limits. Rather, it tends to be the opposite: "oh, you didn't want me to jump off the stairs and dive headfirst in to the couch? OK sorry" and then that's that, they're on to something else.
There are so many factors that it's hard to make any kind of blanket statements. Like any children, age will be a factor - watching younger kids may be more like herding monkeys (as with many young kids, ADHD or not) and older kids, even with attention defecits, will probably be more mellow.
My oldest son (15) has ADHD-i (meaning he's mostly inattentive, not hyperactive) and watching him when he was younger was no different from any other child other than knowing that you might have to ask a question more than once or repeat directions.
My middle son (9) probably doesn't have ADHD per se but is rather loud, obnoxious, rambunctious and can have poor impulse control (meaning do first, think second). A lot of his friends are like like him - loud, boisterous, and energetic. Some I know are being treated for ADHD and some are not. In any case, they tend to be very active together but don't require any special supervision. At their age, they are old enough to follow the rules. Like most 9 year old boys, they are either playing outside in our yard (trampoline, bikes, scooters, rollerblades, hockey, lacrosse, golf) or will play video games, minecraft or legos.
I have some kids in my Sunday school class (6 & 7 year olds) who have a lot of energy and perhaps some inattentiveness. If one of the boys in my class is particularly atsy, I'll have him run a lap or two around the gym to burn off some energy and settle down. For some other kids, they just need a little more direction and reminding than the rest of the class but usually a gentle reminder or even a hand on the shoulder is enough to get them to settle down and get back on track for a few minutes.
Overall, I don't think that one can really make any blanket statements about kids with ADHD. You're watching boys. Give them plenty of options of things to do, let them have at it, and enjoy!