I know the title must have you a little curious. Don't worry, I'm not going to start a physical fitness campaign (even thought it's a great idea), at least not for my dear readers. I'm talking about exercising your rig. Most folks with 5vers don't have much to worry about if they use their tow vehicle regularly. Motorized RVs are a different breed and diesel RVs even more so. A good place to start is with the misconception about mileage. Strange as it may seem, a high mileage, well maintained diesel pusher may be a better buy than a similar, low mileage unit. Well maintained diesel engines can easily make 500,000 miles and a lot of truck engines don't get overhauled till the million mile mark. Diesels, and their drive trains, plus other components, do not fare well sitting idle. Algae can breed and grow in the fuel and condensation and moisture can infiltrate the air and fuel systems. A Class A coach, especially a diesel, is meant to stretch its legs. If you have a diesel and have to sit, start and run the generator under load weekly. A lot of diesel owners don't know that they can adjust their idle with their cruise control; just like truckers. If you have that feature you should always sit at high idle (around 1000 rpm) if parked for any length of time. Like the generator, you should also run your diesel engine at high idle weekly. One area that diesel owners neglect is the care and maintenance of their air system. Most diesels have air bags (which makes the ride so wonderful) and air brakes. Most also have a drier, because clean, dry air is a necessity for the system to work properly. The drier will have a filter and desiccant cartridge that should be changed annually. Periodically, the brakes should be bled down and allowed to recharge. The brakes also have slack adjusters that should be inspected regularly. You can conduct a Google search on all of these things or visit a truck maintenance facility and ask some questions. Although mileage is a factor when considering the purchase of a gas rig; don't forget that most folks don't put a lot of miles on them on an annual basis. If you're a weekend warrior, a well maintained gasser might be right up your alley. Either way, if you're going to sit for any length of time, the same advice vis a vis exercising applies. Finally, PLEASE weigh your rig when you are loaded and ready to hit the road. For one thing you don't want to overload it and it gives you a target for setting your tire pressure. IMHO you should purchase a TPMS (Tire Pressure Monitoring System) if your rig doesn't have one. Finally, after years of experience and owning both class A's and 5th wheels, here's my advice. If you think you're going to travel a lot and utilize your rig regularly a diesel pusher is the way to go. It causes me heartache to see expensive diesel pushers parked and ignored. A well trimmed out 5ver also works fine for fulltimers or over the road travel. If you long term camp or use your rig for things like work or as a park model, a motorized rig is not the way to go. Some may argue, but a Class A gasser just doesn't work for extensive travelling. Most lack the air ride and heavy duty chassis found on a diesel pusher. The lighter chassis also affects your load capacity. Hopefully, this has been helpful and enlightening. Now, go out there and exercise!