Hmmm...belts.
I agree that you probably won't need a belt for deads. But let me explain.
You could compare a belt to an UWH players glove. Yup thats right a glove. You probably have little use for it until - well until you need it. By then it's too late right?
A proper belt sevres a couple of functions for a wieght trainer;
- allows the abdominals to push against something solid
- increases the internal pressure of the abdominal cavity
- restricts the movement outwards of the abductors
- looks good (only joking LOL)
(all of the above points are conjecture as science doesn't always agree. Mind you millions of lifters for decades do so what does that tell you.)
The reason you want to increase the support around your middle may be as follows;
- thats where you will bend (or snap!)
- the pressure supports the lower back
- pushing your abdominals out without restriction will result in - yes you guessed it - a stomach region that sticks out. Often referred to as 'lifters gut', often mistaken for 'roid gut' (thats different of course)
- the presence of the belt reminds you subconsciously to maintain correct for throughout the lift
- hernia prevention (maybe, not really proven but a nice incentive to use one)
A deadlifter will tell you that a belt at the bottom of the lift really doesn't help much as the spinal erectors don't sit flush against it. Mid way however the belt does start to have an effect which continues to lockout.
Now the 'King' Squats is a different matter. I did say dress properly for the King. A belt would be considered appropriate dress for
anyone lifting their body wieght or above.
Reasons are the same as above. Except during a squat the belt is effective throughout the lift.
Like all training questions the answer lies somewhere in a 'grey fuzzy place'.
I personally use one for big compound lfts but only when i'm going very heavy (ie, deads, squats, clen & jerk, power cleans etc) but i discard it all other times.
Here's an article that explains further