adusting treadmill belt
 

I have an older Proform treadmill and the belt is starting to go off to one side and isn't in the middle anymore. It doesn't feel loose, but it's hard to "move" it back to the middle. Does anyone know how I can adjust it?

i turn the treadmill on at a relatively low speed like 3kms per hour (sorry mine's in kms) and with my hands push it while moving like 6 times in a row untill it gets to the middle but unfortunately after i use it the problem occurs again so i have to do it later.