The Problem with Dumbbells.

Progressive Loading Impossible.

The key to building muscle & strength is progressive loading. Beginners can easily add 2.5kg on the bar each workout. With dumbbells you’re adding 2.5kg per hand. Systematic increases of 5kg (both hands) lead to stalling sooner.

No Quality Leg Workout.

Dumbbell Lunges, Step-ups & Dumbbell Squats will never stress your legs as hard as Squats & Deadlifts. Furthermore, as the weight gets heavier, it will be harder to grip the dumbbell while doing the workout. 

Time Consuming. 

 For adjustable dumbbells, changing the weight on these takes longer than changing the weight on a barbell. Unless you have tons of dumbbells, you’ll lose time adding & removing weight. 

Harder to get in position.

 When you're pressing a lot of weight, barbells often prove more practical, as they are already set in an overhead, bench-press position. By contrast, you have to lift dumbbells from the floor, a difficult maneuver if you're pressing heavy weights.

 

Dumbbell vs barbell for bench press

Range of Motion

The pectoral major (chest) is a fan shaped muscle that extends from the sternum and attaches to the humerus bone of the upper arm. In a nutshell, the main role of the pectoral muscles is to make your upper arms move across the front of your torso – a movement referred to as “horizontal adduction”. When this muscle contracts it shortens and pulls the upper arm, moving it towards the middle of your chest.

When you use a barbell, your range of motion is limited. Picture yourself pressing a barbell. Your hands are locked on the bar and end up out and inline with your shoulders at the top of the movement. You upper arms are positioned slightly out to the side of your torso.

Why?

Because your hands are gripping the bar and can’t move any further. They’re locked in this position. Having them stuck in this one position means your arms can only travel so far, restricting the muscles full range of motion.

Now think about pressing a dumbbell. Where are your hands and arms at the top of the movement? That’s right. They’re able to move inline with the middle of the chest. Your upper arms can move further across your chest because they’re not locked in place by gripping a solid bar.

barbell and dumbbell range of motion

When using a dumbbell, your hands, and consequently, your arms, can move more freely. Not being limited to a short up-and-down range of motion permits the press to be performed with an arching movement, which provides greater horizontal adduction. In other words, your pectorals move more and work harder, allowing you to get a good squeeze of the chest muscles and placing them under tension through a wider range of motion.

Muscular Symmetry

Almost everyone has a dominant side. No, we’re not talking about a take-charge personality trait – rather, a tendency to favor one side of the body. For example, most people are right-handed. As a result, their shoulder, biceps, forearm, and hand are slightly stronger or more developed on the right side than on the left.

Even if you aren’t aware of it when performing the movement, your dominant side will, to a certain extent, “help out” the weaker side. Over time, this can cause any existent imbalance to become visibly pronounced, reinforcing not only one-sided muscle dominance and reduced stability, but diminishing the much sought-after visual symmetry that a balanced routine can provide.

Whenever I use a preacher curl machine for biceps I always perform my sets one arm at a time. The reason being is that my right arm is slightly stronger than my left. If I were to use both arms on this machine then my right arm (the stronger arm) would do more of the lifting, particular as I reach failure. This would mean that my left arm is getting less resistance, and therefore less stimulating tension.

The barbell press can create a similar problem. If your right side is slightly more dominant then you’re naturally going to press with more force on your right side, sometimes even contorting your body slightly in favor of your stronger side.

The result of this can cause size and strength imbalances across different muscles. Your right bicep, chest or shoulder becomes more developed than you left.

How do you stop this from happening?

Simple, make sure that each side of your body receives equal tension from the given exercise.

Dumbbells again provide the solution. When using a dumbbell instead of a barbell it means each side of the body works independently to lift the weight. Your dominant side can’t “help out”. The result will be balanced development of strength, size and stability.

Muscular Tension

When you’re using a barbell the natural tendency is for your hands to move outward as you press the weight. Most people don’t even notice this happening when they’re doing a barbell bench press. But this slight outward push of the arms when pressing causes other muscles to come into play, shifting some tension away from the chest. The triceps and shoulder steal some of that muscle building tension.

This is something that you must avoid if you want to maximize chest growth. You want as much tension as possible across your chest with every rep.

As I mention in the first part of this post. Dumbbells allows for the chest muscles to contract over a greater range of motion, resulting in the muscles being under tension longer. Dumbbells also place the chest muscles under slightly more tension than a barbell.

When you press with a dumbbell you don’t get that slight outward push with your hands. There’s more of a natural inward press as the arms come across the front of the body. The chest muscles are forced to work more, resulting in greater tension and muscle fiber recruitment of the pectorals.

outward tension

Conclusion

Dumbbells add a stabilization challenge & let you work both sides equally in case of muscle imbalances. This makes dumbbells great for assistance exercises, but not for main exercises.