Everybody knows that the most basic chest-building training routine includes the bench press. If there's one exercise you're not supposed to leave out, it's this.
But is it really, truly necessary?
I've been doing a lot of reading by Sean Nalewanyj. While he says that barbell chest training works, "it’s just that they don’t offer any advantages that a basic dumbbell press won’t give you." When I read that I was like, Hmmmm... It got me thinking, because I actually can't stand this exercise. I typically will opt for reverse grip barbell exercises since the traditional grip pinches the palms of my hands. So, if I can avoid the barbell chest routine altogether, and still make gains, HELL YEAH!
Pectoral growth comes after the breakdown of muscle fibers, which occurs mostly during "horizontal adduction,"--the movement of the arm across the body.
Nalewanyj says, "[s]ince barbell bench presses lock your hands onto the bar and force you to press in a straight up and down motion, the total amount of horizontal adduction you can achieve becomes limited. This reduces tension on the pecs and shifts more emphasis onto the triceps and front delts. Dumbbells, on other hand, allow you to press in a more natural arching motion which maximizes horizontal adduction and moves your pecs through a larger range of motion."
This is great news for people like me who hate the barbell press. I actually love the flat-seated dumbbell press exercises. My hands don't pinch and I feel more in control of the weights.
Take a look at IFBB Pro, Jeremy Potvin. While I can't comment on his training routine, you can see how symmetrical his body is. One of the major benefits of opting for dumbbells is that it requires the weak parts of your body to build strength.
Barbells tend to allow the strong parts of your body to compensate for the weaker parts of your body. Do this sort of thing long enough and you'll begin to notice asymmetry.
Genetics have a role in symmetry, true, but you can overcome much of that by treating dumbbell training as core, versus barbell training.