Belts are not necessary to get strong but they do provide many benefits to a lot of lifters, namely the ability to use more weight. It also seems to work well in teaching certain individuals how to hold their air and keep their abs tight throughout a lift.
In reference to the "core muscle" arguments taken by both sides, I don't personally buy into either (look to OR's post for the usual argument). I've spent just as much time with a belt than I have without; you will get stronger either way. If your beltless squat movse up, so will your belted squat. If your belted squat moves up, so will your beltless squat.
As for the argument of being more prone to injury when not using a belt... something else I don't buy into. The lift is only as safe as the form and technique used. Lifting with a belt does provide your lower back with greater support, but the loads used are also heavier. In my eyes this cancels out any safety benefits because the lifter is still at a point where load can cause a deterioration in form which can cause injury.
After a long period of relying on a belt, I ditched it. I've continued to get stronger and can still walk upright. I've also found, for me, that its much easier to hold the correct positions in my lifts without a belt... it often got in the way or changed the path of my movement.
In the end, I don't think it really matters. Belt or no belt is a small matter of personal preference and as long as the lifter continues to progress and get stronger it doesn't matter.
Last edited by Pull14; 02-21-2012 at 05:04 PM.