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Ask the seller questions about the equipment. Test out all the elements of the equipment before you buy it. Inspect the outside and inside of all equipment.
Make a list of questions beforehand to ask when you inspect the equipment or before you even go to look at it. Here’s a list of questions you might want to ask:  Does the machine run? How long have you had this? How often has it been used? Why are you selling it? Is it missing any parts? Does it require any maintenance? How much did you pay for it? In what year? Where did you get it? Turn on and try out every piece of equipment before you buy it. If a treadmill or a stationary bike has an emergency stop button, make sure that it works. Try a variety of speeds on treadmills and weights on other fitness equipment. Unplug and plug everything on every piece of equipment. Make sure that there are no frayed wires, rusty gears, or excessively worn pieces of the equipment you’re buying. Gentle wear and tear is okay, but keep an eye out for anything that looks as though it’s about to break. If anything needs to be replaced, see how much the replacement would cost and if it would need professional maintenance.