December 4, 2011

Barbells VS. Dumbells - A Pressing Matter

The Pros And Cons Of Barbell Pressing

Pros

Lifting heavy is much more practical, and energy conserving


·        There is less energy wasted unracking a bar to perform a set compared to having to launch multiple dumbells into position above the chest/shoulders. If a workout calls for loads at, or above 90% of max, then a barbell should be the only consideration, as the effort needed to get the dumbells into position to begin the set, along with the risk involved with using near maximal loads in a position which challenges stability, outweighs the possible benefits of performing a few near maximal reps.

More weight can be lifted because of the increased stability

·        With a barbell, there is a relatively large base of support below the center of gravity – the base of support consisting of two points of contact (both arms) which lie outside the center of gravity (the center of the bar). With dumbells, there is a relatively small base of support below each separate center of gravity – the base of support consisting of one point of contact (the hand) which must remain beneath the center of gravity (center of each dumbell) for both dumbells, or stability is lost, and force production is compromised. This means it is a lot easier to stabilize a bar, since its center of gravity remains relatively centered over the base of support, thus facilitating greater amounts of force to be produced. Because dumbells travel medially/laterally as they are raised/lowered, it is a lot more demanding for the nervous system to effectively coordinate the movement in such a way that the base of support remains under the center of gravity, which compromises force production. This is why more weight can be lifted with a barbell as opposed to dumbells – roughly 10% more weight in most cases.

Intention can increase muscle activation

·        Because a barbell is a fixed piece of equipment, medial or lateral forces can be applied to the bar, to increase the recruitment of either the chest/shoulders, or the triceps. Intentionally trying to bring the hands inward while raising/lowering the bar increases the demand placed on the muscles responsible for bringing the arms inward – chest and shoulders. Intentionally trying to pry the hands outward increases the demand placed on the muscle responsible for extending the arms outward – triceps (and to a much lesser extent, the rear delts, which contributes to increased stability of the shoulder girdle, facilitating the use of greater loads).

Cons

Greater risk of injury

·        Because a barbell is a fixed piece of equipment, the nervous system’s natural ability to share the load is limited, which elevates the risk of injury, especially to the shoulders, as the body is essentially locked into position, which can be potentially dangerous under heavy loads, or as fatigue sets in.

Easier to cheat

·        Because of the sense of security that accompanies the increased stability provided by a barbell, it’s common to get brave and attempt to complete reps that wouldn’t normally be considered, by instinctively relying on the stretch reflex to assist with the lift. This becomes problematic when performing reps in this way develops into a habit over because it has proven to be successful. Consistently utilizing the stretch reflex to perform reps can cause irreversible damage to the connective tissue, resulting in a permanent loss of motor control.

Imbalances can be created below conscious awareness

·        Because both arms contribute to lifting the same piece of resistance, it’s possible for one side to take on a greater percentage of the load beyond conscious awareness, resulting in imbalanced development which undoubtedly will become a limiting factor at some point down the road.

The Pros And Cons Of Dumbell Pressing

Pros

Cannot compensate with the stronger side helping out the weaker side

·        Because both sides are individually loaded, each side has to do its own work, and cannot rely on the opposite side for assistance, the same way it could if both sides were working together. This can both prevent, and correct, imbalanced development between each side.

Greater range of motion allows for more complete muscular development

·        In most cases, dumbells offer a greater range of motion, which facilitates growth in a few ways. First, the muscle that is stretched the most, is recruited the most. Second, the greater the range in which the muscle remains under tension, the more fibers that are stimulated. With a barbell, the range of motion is limited by the thickness of the chest cavity at the bottom of the range, and the hands not being able to travel inwards at the top of the range. Dumbells are not affected by this as they can be lowered further, by bringing them down, and to the side of the chest cavity, and raised higher by bringing them in towards each other as the arms extend over the head/body – the exception being dumbells that only a select few are strong enough to use, which are so wide that they are limited by their own width, to the point where the plane in which the hands travel is almost identical to the width in which the hands remain when pressing a barbell. For optimal growth, muscles need to be under tension at their longest, and shortest range, and the increased stretch at the bottom, combined with the increased range at the top, make dumbbell presses a more complete movement.

Offset grip can increase muscle activation

·        By holding the dumbell with the thumb side of the hand tight against the inner bell, the center of gravity is slightly shifted outside the base of support, which increases the demand on the muscles responsible for bringing the arms inward – chest/shoulders.

Cons

Can’t use as much weight

·        Because of the increased neurological demand that comes with needing to stabilize multiple pieces of resistance, along with the effort required to get heavy dumbells into position to perform a set, it is not possible to use the same amount of weight, for the same amount of reps, as is possible with a barbell.

Which one is better, and why?

Because the body adapts to everything, neither is better. However, both can be used to better each other. Barbell presses can increase strength levels so that greater loads can be used to build muscle with dumbells, and dumbbell presses can be used to stimulate growth and correct imbalances, increasing the potential to demonstrate strength with barbells.


If you have any questions regarding the differences between barbell and dumbell presses, feel free to contact me at ben@paramounttraining.ca. I'm available for online consulting and personalized program design, as well as one on one training if you are located in the Greater Toronto Area (GTA).

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