FJ, mine has shock absorbers in it - great on my knees I don't srping like I'm moonwalking but it is kinder on the body.
Perhaps think of the kind of functions you'd like it to have. I can set mine for time, calories, distance etc. I also have 4 or 5 set programs and the option to add 2 more I design. I would like it to have interval training but it doesn't, I have to manually do that which is a PITA.
Also think about storage. When ours is not in use we can fold it up so it takes a fraction of the space.
Also, warranty!!!! BIG issue. Ours is a little over 12 months old and we recently had issues with it shorting out (turned out to be the power point at the wall) and I was panicking until I realised the warranty we have.
Definately look at the speed it goes to. If you want to do serious running, you might need it to go more than the 9Km/hr most lower end tradmills go to.
I agree testing a few to see what you like and to see how fast certain speeds are.
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