I hate going to the gym. Seeing other people moving in the corner of your eye and trying not to look at them, not being able to watch what I want on TV, having to wait for equipment, having to drive to the gym and then either use the gym shower or drive home all sweaty, etc.
Why can't the gym come to you? I'm thinking you should be able to order a gym and have it come to your house similar to how you order a pizza.
A business could fit a couple pieces of workout equipment in a camper or trailer pulled behind a pickup truck, and when you feel like working out, you could call them and they can park it in your driveway for an hour. There would be a phone app for ordering and scheduling a time. You could set up a regular appointment time if you wanted.
You could have them just drop it off and leave, for like $10 for a single hour session ($5 for a half hour), and maybe $50/monthly for 3 hour sessions per week, which is only a little more expensive than a gym.
Since you can fit 2 pieces of equipment in the trailer, you could have a personal fitness trainer come with the gym truck and you and the trainer would each have a copy of the workout machine.
I'm thinking it would mostly be for cardio, like treadmills, ellipticals, etc, but also rowing machines and workout towers like Bowflexes
The gym truck could have a TV and air conditioning. Or since it will be at people's houses, they could use their own TVs, or more likely laptops or tablets.
I'm thinking you would have to have the gym equipment on a platform with bubble levels and cranks to quickly adjust the floor so that the workout equipment is level in case you are parking on a slight hill. The workout equipment would probably be physically attached to the platform and the platform would be taken in and out of the trailer using a HiLo.
Alternately, you could have people rent the gym trailer and keep it at their house permanently, but I don't think that is practical for most people because they might need city permits to keep something permanently parked in their yards. Plus they would be easy to steal.