I might touch this up and make it into an academic quality paper. Then I can use it in job interviews as a writing sample as part of my job interview presentation. But for now I will just keep it casual. It is 100% accurate but I am not going to page for page source hunt.
When in a gym (provided you have been going, evil eye to you know who) you see others running around with lifting belts. At some places like Home Depot you see the stock people in them as well.
Do weight belts work and how? Yes they do work, here is how. Look at the lumbar spine cut away picture at the top. We humans walk upright, and need our spine to give support yet be flexible to absorb shock, while also able to provide range of motion so we do not walk like robots. The spine as you know is many disks stacked on top of each other, with a spongy disk in between each to provide cushioning. The only real support your spine has are muscles the erector spinae and the transversospinalis groups. Think of your spine as a bunch of stacked soup cans held together with rubber bands. The figure 12 picture shows how this looks. When you wear a weight belt it will compress the fluids and tissues in your abdominal cavity together giving increased support the the lower spine. This relieves the Erector muscles of much of their burden as the fluid pressure hold the spine in place.
This can work against you while trying to reach fitness goals. People who wear a lifting belt all the time during resistance exercise deny the erector group stimulus to adapt to. The rest of the skeletal muscle adapts and become stronger, but the erector and other spinal muscles remain in an less or even de-conditioned state. This creates a dangerous imbalance vastly increasing the changes of injury.
The proper times to wear a lifting belt is. 1-when a power athlete is in a peaking phase and is training an 3 Rep-max range or higher. 2-When athlete is doing conditioning that requires heavy repeated lower spinal loading while near an exhaustive state. The exhausted spinal muscles could relax and cause a disk to herniate. 3-When the athlete is recovering from low back injury. The belt will keep the disks and muscle in proper alignment for healing, while client does no spine loading exercises. Once the low back is recovered sufficiently the athlete may return to spinal loading exercise under the supervision of a doctor or physical therapist.
Athletes and exercisers must be trained to self monitor loads on the body to decrease the chances of injury. Everyday life and many athletic events do not have people wearing weight belts, so the law of specificity says to decrease injury, allow the spinal muscle to exercise and adapt along with the target muscle groups.
The Original 
