What’s the best chest Exercice?

It depends on how your structure distributes tension.

If you’re shoulder-dominant (front delts take over pressing), a flat or incline press will shift load away from the chest. In that case a decline press or even starting with a pec deck works better because it biases horizontal adduction and keeps tension on the pecs instead of the delts.

If you have long arms, pressing becomes more triceps and shoulder heavy because the moment arm is longer and the lockout dominates. You’ll often feel presses in triceps before chest. A pec deck or any fly variation becomes more effective to actually load the chest, or you keep presses but stay in the bottom half where pec tension is highest.

If you have short arms, presses usually feel great because you can keep tension on the chest through more of the range. In that case a chest press machine can already cover most of the stimulus and the pec deck is just a finisher.

Your rib cage shape changes everything. A big rib cage with good thoracic extension puts the chest in a naturally stretched position, so presses become very effective. A flatter rib cage makes it harder to create that stretch, so flies or pec deck often give a better stimulus because they force the lengthened position.

Clavicle width and insertion points matter. Wider clavicles and good pec insertions make pressing patterns align well with the fibers. Narrower structure or higher insertions often make the chest harder to engage in presses, so shortened-position work like pec deck helps build connection and tension.

Your scapula control is key. If you can’t keep scapula retracted and stable, presses turn into shoulders and triceps. Machines help, but pec deck is even simpler because it removes most stabilization and lets you focus on pure adduction.

Your strength curve also matters. Some people are stronger in the stretched position, others in mid or shortened. If you’re weak in the stretch, a press machine is more important. If you’re weak in contraction or can’t feel the chest, pec deck first works better.

Finally, your injury history and joints decide a lot. If pressing irritates shoulders or elbows, pec deck becomes the main movement because it’s more joint-friendly and easier to control deep ranges safely.

So in practice, press is better when your structure lets you load the chest in the stretch without delts/triceps taking over. Pec deck is better when your structure shifts tension away from the chest, when arms are long, rib cage is flat, or you lack control and need a pure contraction movement. Optimal setup still uses both, but which one leads depends on your anatomy and weak points.