Charles Poliquin is one the world’s most successful strength coaches, having coached Olympic medalists in 17 different sports. He is based in The Rockies, Colorado.
If you come from the same genetic stock as Ronnie Coleman, you can just do a handful of arm exercises and experience phenomenal gains in arm size and strength. For the rest of us non-mutants, a variety of exercises are required to propel past plateaus in arm size and strength.
Even with above average genetics you’ll still experience better results working with a wide repertorie of exercises. The order of recruitment of motor units is fixed for a muscle during a specific exercise. This means that certain motor units have a low recruitment threshold for one exercise and a higher recruitment threshold for another exercise. Changing exercises also allows you to target specific points along the strength curve. For example, barbell curls target mainly the mid range of elbow flexion, while Scott curls target primarily the beginning range, and incline dumbbell curls the end range.
By intelligently selecting exercises you can ensure all points of the strength curve have been adequately trained, resulting in superior development.
Triceps: the elbow extensors
The triceps has three heads: the long head, the lateral head and the medial head. Because all three heads of the triceps join at a common tendon to insert on the ulna (elbow bone), it’s impossible to purely isolate one single head of the triceps.
However, by changing your body position to change the orientation of your upper arm in relation to gravity and to your torso, you can affect the percentage of contribution of each muscle.
The association between the exercise selected and the targeted head comes from a variety of sources emanating from the research of P.A. Tesch to the writings of Frédéric Delavier. Here are some specifics.
The long head
The farther away the arms are from the belly button, the more recruitment of the long head of the triceps.
Exercises that would fit this definition are triceps extensions performed on an incline bench (incline position) and the overhead triceps extension (perpendicular position).
Key concept: It is involved in all overhead pressing work
Key moves: lying EZ-bar extension, overhead dumbbell triceps extension with reverse grip, pushdown with straight bar and narrow grip, EZ-bar pullover with narrow grip.
The lateral head
Performing triceps exercises on a flat bench will increase the contribution of the lateral (and long head) of the triceps.
Key concept: The more the upper arm is internally rotated, the more the lateral head is activated. Therefore, the decline elbows out narrow-grip bench press is the most bang for your buck exercise for the lateral head (adding bands or chains, makes this exercise even more effective).
Key moves: lying dumbbell triceps extension, standing barbell French press, pushdown (straight bar and narrow grip), one-arm triceps pressdown pronated (overhead, bent forward, rope extensions), narrow-grip bench press, press behind neck, dumbbell kickback, seated semi-supinated dumbbell press..
The medial head
As the arms get closer to the torso, such as during exercises performed on a decline bench, there’s an increase in the contribution of the medial head of the triceps at the end of the range of motion.
Key concept: It is considered the workhorse of elbow extension, hence works in all exercises.
Key moves: standing barbell French press, one-arm triceps pushdown (pronated), narrow-grip bench press, dumbbell kickback, press behind neck, semi-supinated standing dumbbell press.
Biceps: the elbow flexors
The elbow flexors are actually composed of four main muscles: the biceps brachii, brachialis, brachioradialis, and pronator teres. However, due to simple ignorance of anatomy most authors group all elbow flexors under ‘biceps’. To maximize hypertrophy, you need to train all four elbow flexors with the exercises and training methods best suited to do the job.
The short head
To work the short head of the biceps brachii, all curls where the elbow are forward to the body, such as concentration curls or Scott curls will do the job.
Key concepts: Involved in all curls with elbows in front of body and especially when done with a narrow grip
Key moves: Scott curl, concentration curl, face-down incline curl (chest against bench), lying overhead pulley curls.
The long head
For the long head of the biceps, exercises where the elbows are behind the body, such as all the various forms of supine incline curls will do the job. The long head of the biceps also responds very well to higher velocity movements.
Key concepts: Involved in all curls with elbows in line with body or moved towards the rear, especially when elbows are turned outward.
Key moves: standing supinated barbell curl, standing supinated pulley curl, seated incline dumbbell curl, seated incline hammer curl, elbows behind back twin pulley curl.
Brachialis and pronator teres
As for the brachialis and the pronator teres, many bodybuilders neglect these muscles. This prevents them from attaining their full potential as the brachialis muscle in particular makes up roughly half of the upper arm elbow flexor mass.
The brachialis is known in the biomechanics world as the workhorse of elbow flexion. That is, it works in all elbow flexions movements whether the forearm is pronated, supinated, or in between.
When the forearm is supinated (palms-up grip), the biceps have an effective line of pull, however, when the forearm is pronated (palms-down grip), the biceps checks out and the brachialis lifts most of the load. This is why you commonly see trainees handle 35% less in reverse curls than they do in barbell curls. However if one trains the elbows flexors properly, that difference should be in the area of 18%. So if you can curl 100lbs, then you should be able to reverse curl 82lbs.
If you don’t already do one of the various forms of reverse curls or hammer curls as part of your workout, the addition of some concentrated brachialis work could easily result in a half inch to a full inch of arm growth in a month’s time.
If you isometrically pause for two seconds at any point before reaching 90 degrees of elbow flexion, you’ll further activate the brachialis. The brachialis and pronator teres also respond favourably to low velocity movements and isometric pauses.
Key moves: reverse curl (EZ-bar, barbell, or pulley), seated Zottmann curl, Scott Zottmann curl, hammer curl, scott reverse curl.
Don’t forget the forearms
The role of the forearms in achieving maximal size is tragically unappreciated. As any kinesiologist will tell you, forearm action contributes to elbow flexion. Therefore, increased forearm strength will allow you to use higher loads in elbow flexion exercises thus creating more tension, and more muscle growth.
Other bonuses of forearm training include decreased risk of elbow flexors tendonitis, as well as better aesthetics and symmetry. An 18-inch arm above a 13-inch forearm looks grotesque, and only genetic mutants such as Casey Viator can sport huge arms and forearms without direct forearm work.
Feel the muscle
Many aspiring men train their arms too heavy. You must learn to control the weight; the weight should not control you, and many trainees have experienced renewed growth simply by slowing down their movements. By keeping the duration of the set between 40 and 60 seconds per set, one will insure the optimal time under tension to stimulate hypertrophy.
Verify neck alignment
Finally, your efforts in the gym can be wasted if the neural conduction to the muscles is sub-par. If you’re stuck in an arm size or strength plateau, an impingement of cervical nerves from the vertebraes C5 and C6 may be impairing neural drive to these specific muscles. Consult a qualified health practitioner and get this issue treated. I often have found over the years that trainees who get great soft tissue work on the anterior muscles of the neck instantly increase their lifting poundages, especially if neck work for the extensors is added to the mix.