Almost every sport has special shoes that ensure better performance. So weight lifting too.
Weightlifting shoes give you an advantage in weightlifting and other strength exercises for two different reasons:
1 – The increased heel of the weightlifting shoe brings your body in a better position to perform squat, snatch, clean and jerk, and bench press technically well.
The raised heel ensures that you can bring your knees further forward in relation to your torso. By moving your knees further forward with a squat, the trunk does not have to tilt so far forward to stay balanced, and you can squat deeper.
Even if you can already squat deeply without weightlifting shoes, you will also benefit from weightlifting shoes. By moving the knees further forward at the squat, the trunk does not have to tilt as far forward for the same squat depth. Because you can keep the trunk more vertical this way, your (lower) back is less stressed on the squat. The more vertical the torso, the less torque on the back, and the less hard the lower back muscles have to work. With weight lifting shoes you need less force in your back to move the same weights.
If your lower back with the squat is a weak point (is common), you can also immediately move more weight with the squat. As a result, the squat also comes more to the leg muscles, so you can train it more effectively.
With the Olympic weightlifting exercises snatch (tug) and clean and jerk (tipping and bumping), moving the knees further forward allows you to “catch” the weights in a lower position before you stand up with them. Because you can catch the weight in a lower position, you don’t have to pull it up as far, which costs less force. That is why you can use heavier weights. Because you can move your knees farther forward, the back remains straight during these exercises, and getting up with the trapped weights costs less force.
When bench pressing, the raised heel of the weightlifting shoe makes it easier to arch (pull the back), while still making full contact with the floor with your foot (required by the competition rules).
2 – You can put more weight on the weights, which results in more effective training and improved performance.
This can be further subdivided into two different reasons:
2.1 You can deliver more muscle strength with improved stability
Research shows that your (leg) muscles can provide more strength if you are on a stable surface (source).
Good weightlifting shoes are very stable. The heel of the weightlifting shoes are made of a hard material such as wood or hard plastics. This means that it does not deform to hardly any deformation under a heavy load. This provides stability in the downward direction.
The other parts of these shoes are also made of sturdy material that does not yield, even if you pull the laces hard when you tie. Most weightlifting shoes also have a strap that can be tightened, which you can usually secure with Velcro. This ensures that the shoe fits even more firmly around the foot. This mainly provides better lateral stability.
A final important feature that helps with good stability is the rubber anti-slip sole of weightlifting shoes. This is usually flat, for a maximum contact surface with the floor. This gives the shoe a lot of grip.
2.2 Less power is lost
Because the heel and sole of the weightlifting shoe are hardly compressible, weightlifting shoes ensure a better transfer of strength. This is in contrast to, for example, running shoes and most sneakers. These intentionally have a compressible sole for cushioning; to absorb forces.
Enough reason to choose special shoes for weightlifting and other strength exercises. However, this does not mean that everyone can immediately use more weight when wearing weight lifting shoes; it will take a while for most people to get used to the new execution of the exercises, so that you can take advantage of it later.