An indoor trainer removes any excuses you can think of for not riding. You can set it up anywhere you like (even in front of the TV) allowing you to continue riding regardless of time of day, nasty weather etc. The less expensive magnetic trainers offer a cost effective option, and are great for riders that just want the occasional 'bail out' option without having to spend too much. Fluid trainers offer a more realistic riding feel due to the way resistance is applied, and are generally preferred by riders intending to use the trainers as a more integral part of their riding. Both Magnetic & Fluid trainers are quieter than wind trainers.