That depends on how you practice.

The pectoral muscles are divided into upper, middle and lower parts. Generally speaking, it is divided into upper and lower parts.

If you feel that the thickness of the middle part of the pectoral muscle is not ideal, I suggest you do more dumbbells or barbells to push straight. These two classic movements are specifically aimed at the thickness of the whole pectoral muscle, especially the middle part of the pectoral muscle.

Use dumbbells at first, and then switch to barbells when the weight of dumbbells is not enough. The distance between your hands holding the barbell should not be too big or too small. If it is too small, the triceps are more involved. If it is too big, the weight of the barbell will be scattered on your shoulders instead of concentrated on your chest muscles, which will put pressure on your shoulders and make you easily injured.

When the barbell rises and falls, the barbell should be concentrated above the nipple and move vertically. This will be of great benefit to strengthening the middle part of the pectoral muscle.

Furthermore, in general, barbell bench press is very effective for thickening chest muscles, but it also varies from person to person. Some people have obvious effect of barbell bench press, while others don't.

I like to bench press with dumbbells, only 40 kg. It has been very effective, but the barbell bench press is not good. I always feel that there are too many arms involved.

Now I mainly use dumbbells, supplemented by barbells, interspersed with some sitting instruments to push my chest.

Thank you ~ ~