>>7212745In my opinion, something along the lines of competition weights. If you're squating like 400 lbs and deadlifting 600 lbs for a PR I see nothing wrong with using a belt.
Though I'm not saying it's stupid to use it at a lower weight then what I just brought up.
>>7212756Lifting belts are like in the picture. What you're talking about is weighted belts, I believe the name is.
http://fit5fifty5.files.wordpress.com/2010/05/weight-belt.jpg