The Brachialis - Often Neglected, And Limiting Factor In Arm Development

The brachialis is a relatively small elbow flexor that, when developed, adds a third dimension to one’s upper arm development (along with the lateral head of the triceps), very much the same way a pair of developed rear delts give the shoulders a three dimensional appearance. When relaxed and viewed from the front, the brachialis ads thickness and width to the upper arm more so than any other local muscle (especially noticeable in bodybuilders in the front relaxed pose). Reigning Mr. Olympia Phil Heath, and former Olympia competitor and bodybuilding fan-favorite Lee Priest, are perfect examples of this as they each display a pair of developed brachialis muscles that seemingly pop out of their arms in virtually every single pose.

Muscle Building Essentials

To specifically target a muscle, with the goal of building it up, it’s important to know a few critical pieces of information to provide direction when structuring a plan, and they are:

·         Is the muscle fast twitch dominant, slow twitch dominant, or of a mixed fiber type? The answer to this should dictate the loading parameters used to build the muscle.

·         What other muscles contribute to the same relative movement, and how can their contribution be limited, so by default the targeted muscle takes on the greatest percentage of the load? The answer to this should dictate how the body is positioned so that the synergistic muscle groups are limited in their contribution.

·         What joint angles/ranges of motion place the targeted area under the greatest stress, and which place it under the least stress? The answer to this should dictate how the exercise is executed.

As it relates to the brachialis, in most cases it’s predominantly fast twitch, and the primary muscles which contribute alongside it to create elbow flexion are both heads of the biceps, but they’re contribution can be limited by performing arm curl exercises with the elbow positioned in front of the body, or with a neutral/overhand grip. In terms of elbow flexion itself, the brachialis has a slightly better angle of pull in comparison to the biceps the more the elbow is extended (through the first 20-30 degrees of elbow flexion), after which the biceps take over as their angle of pull begins to improve. Therefore, the best way to prioritize the brachialis in most cases is with heavy weights, lower reps, higher sets to make up for the lack of volume per set, while performing movements with the elbows placed in front of the body, with the palms facing each other, or the floor, and by performing only the first half of the movement.

TIP: Regardless of whether the hand is supinated, pronated, or neutral when performing arm curls, pausing during the concentric phase of the lift between the beginning and middle phase (basically 90 degrees or less of elbow flexion) of the lift will increase the amount of work done by the brachialis, since this is the range in which it is most active.

The 15% Advantage

Because the sum of the muscles responsible for elbow flexion is greatest when using a neutral grip, you should be able to lift roughly 15% more when performing a hammer curl per se, in comparison to using an underhand (supinated) grip. If this is not possible, it may suggest that there is a relative imbalance between the brachialis and the biceps, which can be further identified by comparing overhand (pronated) curl strength, to underhand (supinated) curl strength. If you can’t curl at least 80% with an overhand grip, as you can with an underhand grip, this would suggest that the brachialis is weak, and by correcting this imbalance through training, the potential for both strength and size gains is elevated.

TIP: If the elbows flare out when performing overhand curls, this indicates that the brachialis is struggling to handle the load, and may be weak.

Exercises

Some of the more common exercises used to target the brachialis are:

·         Zottman Curls (Standing or Seated/Incline)

·         Hammer Curls (Standing or Seated/Incline)

·         Cross-Body Hammer Curls (leaning in, performed uni-laterally by curling the dumbell across the body towards the opposite shoulder)

·         Reverse-Grip Preacher/Spider Curl

·         Reverse-Grip Standing Barbell Curl (Straight-Bar or EZ-Bar)

·         Cable Curl w/Rope, Reverse-Grip Bar Attachment, Single-Arm Overhand

If you have any questions about brachialis training, 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).