If you believe that increasing the size of your muscles will help improve the deadlift, then focus on training the muscles that received a 3 or more on the above scale. Give it 3, 6, even 12 months of hard training. Track your progress and try to establish your own personal correlation between your muscle size and your performance on the platform. It is worth noting that because the deadlift requires force to cross the most stable major joint in powerlifting (the spine/hip) adding size doesn’t tend to have the same impact to the lift as it might other lifts (particularly the bench). This is why this lift is the typically the least affected by any change in bodyweight. However bigger and stronger engines (glutes, quads, erectors, hamstrings, forearms) that help move and control the sumo deadlift can still significantly improve performance.
The Inzer Lever Forever Belt is a serious and high quality bit of kit, whether you buy it in its 10mm or 13mm incarnation. It’s undoubtedly belt suited to powerlifters and strongman competitors; weightlifters and Crossfitters may find that the sheer bulk of the belt interferes with the range of motion of the snatch and clean and jerk. That said, even those lifters will be hard-pressed to find a belt that offers this much support when squatting. Make no mistake, if you’re currently using a small tapered belt, this thing is almost certainly going to put kilos on your squat.
Gaining this muscle mass can be very beneficial, and is by no means a new concept. As lifters we must train for strength first and foremost, but there are times when it is helpful to train some extra lifts “like a bodybuilder.” Packing on muscle in the right places to compliment what is left lacking by the main lifts will ensure that you give yourself a chance to later strengthen some of your weak areas—which likely negatively affect your technique on the main exercise or limit your ability to execute it under progressively heavier weights. Additionally some bodybuilding training can be used to build up the stabilizing musculature or antagonist musculature in a region of the body to keep the body in balance.