JD asks to go out, especially in warm weather. I think inside environments are relatively 'sensory anemic' for cats. JD has adapted well to being indoors, but still likes to go out and bask in the sun, sniff the wind, and watch for critters and creepy crawlers. I'm unwilling to let him roam outside on his own, so we harness trained him. He's usually ready to come in after 20 minutes to a half hour, and we don't usually cover more than 100 feet of the backyard, but he's always much mellower after his walks.
He doesn't like wet feet, though, so on rainy days or snowy days, he won't go out. That means he's inside all winter, which is hard for him, but it makes spring walks all the sweeter.
I have to say, though, that getting a cat trained to harness is not a piece of cake. It's a little like herding goats...or herding cats, for that matter
I'd forgotten how 'entertaining' the training can be until we got Dusty. She's a work in progress, but at least I have JD around to remind me that it
can be done.