I have never used a belt deadlifting and have no plans to.
Belt or No Belt
Some people don't use a belt, which is fine.
However, research demonstrates that wearing the Belt increase dramatically increase Intra-Abdominal Pressure, which provide greater support for the lower back compared to lifting without it.
The greater your core stability (stiffeness), the more force a lifter is able to generate, which has to do with...
"Leakage'"
"Being able to stabilize the pelvis in the frontal plane as we move is important otherwise we create a disconnect in the connection of the muscles.
Dr.
McGill calls this a "
leakage" of energy, and the knees and low backs generally pay the price. "
The Weak Link In The Chain
I've posted information on this before. The core is usually the weak link in the Squat and Deadlift. That means the core gives out long before the legs do.
The core ends up being Overloaded while the legs are Underloaded. For individual interested in maximizing leg development, wearing a Belt allow them to minimize "Leakage"; this core stiffness ensure more work is placed on the legs with eithera heavier load or more repetition.
What's even more effective are exercise that minimize or completely eliminate the core from the movement; Leg Press, Belt Squat (great carryover movement for the Squat), etc.
The core is then strengthened with exercise that directly focus on it.
My reasoning for deadlifting without a belt is simple - I deadlift to make me stronger for the rest of my life, not to maximize the weight I can lift within the rules of my division. ...One has to ask, "What's the goal of performing this lift?" If it's to enhance the quality of one's life, I don't see how wearing a belt helps that. One has to ask, "What's the goal of performing this lift?" If it's to enhance the quality of one's life, I don't see how wearing a belt helps that.
The Purpose
If an individual is lifting for health, there's no reason for wearing a Belt or even lifting heavy for low repetitions.
If an individual is a competitive lifter, a Belt will help the majority of lifters.
So, the right answer is dependent on your objective.