For someone who is going to simply walk... and do not do too much of that or you will need the Treadmill Doctor.
The Proform Performance 400 barely makes the grade for a committed walker, and we can't recommend this to runners. Servicing and parts replacements will most likely bug the user in the short term, and Icon's poor customer service will cause concern. Serious runners need to look at higher quality treadmills priced $1,500 and above for strong results. If you are a serious user, seriously walk away from this machine. If you are going to baby it and take care of it like we suggest, it is borderline whether it will work long-term.