To Curl or Not to Curl?
In bodybuilding, an exaggerated arm size is part of the "look" and few can achieve that without at least some direct arm work. If your goal is to compete in bodybuilding, or you want a bodybuilder-like physique, you'll likely need direct arm work.
But most people won't need direct arm work to get their arms relatively muscular and proportionate. Simply training hard on the big basic lifts, especially the various presses and pulls, will get you there. Sure, there are exceptions. But those shooting for a strong, athletic, jacked look, won't need direct arm work.
Let's break that down.
I'm not against direct arm work. You can read the advice I've given before on it. But the body has a limited capacity to handle systemic stress from training and you don't need to train every muscle group equally.
Look at your training time and effort like money. You need to invest it where you'll have the greatest return possible. Simply put, invest more training money on muscles that you want to develop the most in order to get the look you want.
I've trained female figure and bikini competitors who only focused on hamstrings, glutes, upper back, and shoulders. They simply didn't need to train arms, chest, or even quads to get the look they needed to win. That's why it's important to know what kind of look you're shooting for and which muscles need to be emphasized to get that look.
You aren't training just to train. You're training to achieve a certain goal, either a certain look or performance improvement. But if you don't know exactly what you want, you can't do exactly what you need to get there.
TC Luoma published an article about research which found no added benefits on strength or hypertrophy when isolation work for arms was added to a training program built on multi-joint movements (1).
The researchers conducted an eight-week study on experienced bodybuilders. The participants were all on the same basic program of multi-joint exercises, but half of them did extra arm work.
After eight weeks, there was no difference in arm growth or strength among all the subjects. So the conclusion was:
"The addition of single-joint exercises to a resistance training program that already contains multi-joint exercises brings no additional benefit in terms of muscle performance and anthropometric changes in trained men, whether they're using anabolic steroids or not. These results might help to design more time-efficient resistance training programs, since it suggests that trained men can save time not including single-joint exercises in their routines and still achieve optimal results."
The only problem? How much can an already experienced bodybuilder progress in just eight weeks? This was the one major limitation that I found with the study.
It's an important one because while a beginner can gain a good amount of muscle at first (newbie gains), after the first two years of serious training muscle growth will become much slower. After three years of serious training, gaining five to seven pounds of muscle in a year is exceptional. You might've gained 20 pounds your first year of training and 10 the second, but it slows down after that.
So if you can gain five to seven pounds in a single year as an experienced lifter, how much overall muscle growth can you get in just an eight-week period?
And if you built 0.8 to 1.2 pounds of muscle in that timeframe, you'd gain that amount across your whole body – not all in one place. So think about that: 1.2 pounds of muscle spread over your whole body won't lead to visual changes in your arms. So the fact that the direct-arm-training group had no significant benefit doesn't mean that there are no benefits at all.
On the other hand, strength is gained faster than muscle mass. And since the groups using isolated arm work didn't get any stronger than the group not using it, we can conclude that direct arm work isn't necessary to get optimal strength gains.
This means you can still get nearly the same overall gains by focusing solely on multi-joint movements, and this backs up what I've seen while training experienced athletes.
If you're a normal person with a full-time job, a family, financial stress, etc., doing more work might actually hurt your results, especially if you're natural. If you can get pretty much the same results without direct arm work, focusing on training efficiency and skipping direct arm work (or doing only a small amount) might end up being beneficial.
Using the proper multi-joint exercises can be as effective at stimulating the biceps and triceps as direct work.
For an exercise to stimulate growth, you must recruit a large proportion of the muscle fibers and you must, at one point during the lift, lengthen or stretch those recruited fibers while they're under load. This is the eccentric or negative phase of the lift.
For example, a muscle could be heavily recruited in an exercise, but if it works isometrically (think abdominals in a squat) it won't be optimal for growth. You'll still get growth and the muscle will still get stronger (mostly stronger isometrically) but you won't get maximal gains.
Bret Contreras detailed the level of muscle activity in multiple bicep and back exercises. He looked at muscle activation (via EMG) in multiple movements. A cool finding is that many pulling exercises had similar, or even superior, bicep activation as direct bicep movements.
For example, a loaded chin-up (supinated-grip) and neutral-grip pull-up had greater bicep activation than all the curling exercises measured. The mean muscle activation for the chin-up and neutral-grip pull-up was higher than the barbell curl, preacher curl, hammer curl, incline dumbbell curl, and dumbbell curl.
However, the horizontal rowing exercises didn't have the same effect on the biceps. In rowing variations, the bicep activation was less than half of what it was for the other exercises.
The take-home message: If you do chin-up or pull-up variations (and likely other forms of vertical pulling like the supinated lat pulldown and neutral-grip lat pulldown) you'll get plenty of bicep stimulation.
But if your pulling work only includes horizontal pulling (barbell row, seated row, T-bar row, etc.), you'll likely need to add some bicep work for maximum growth.
Now, anecdotally we know that horizontal pressing greatly stimulates the triceps. Close-grip bench presses and dips are two of the best triceps builders out there. In fact, the triceps likely need even less direct work than the biceps.
If your goal is to build an athletic muscular physique, you likely don't need direct arm work. Skipping it can allow you to either recover faster from your workouts or invest in a bit more volume on multi-joint movements without exceeding your systemic capacity to handle stress.
Not sure how much (if any) direct arm work you should do? Just see which of these categories best describes you.
1. Lifters who don't need ANY direct arm work:
- Most athletes. I include CrossFitters in this category.
- Those who just want to look athletic. Imagine a MMA-type look, a sprinter, or a good CrossFit competitor: good shoulders, solid legs, a muscular back, round pecs, and arms that are in proportion with the rest of the body.
- Those who have great arm genetics or a physical job. Sometimes even bodybuilders belong in this category. Here's an example of a competitive bodybuilder trained by Jean-Philippe Ferland. His arms really stand out, yet he doesn't do any direct arm work. Good genetics and a physical job (where he carries heavy stuff and does lots of sledgehammer work) make the direct arm work unnecessary.
- Those who want to be big and strong. Most strongman competitors and a lot of powerlifters do zero bicep work and very little tricep isolation work. Most Olympic lifters don't do direct arm exercises.
2. Lifters who need SOME direct arm work:
These lifters don't need as much direct work as they might think. One direct bicep and tricep exercise twice per week is plenty.
- Those who have a mechanical disadvantage when it comes to stimulating arms, even if they do plenty of vertical pulling and horizontal pressing work. People with long arms tend to be able to target the pecs and lats easily when pressing and pulling, but they get less bicep and tricep stimulation during these lifts. They'll likely need a bit of direct work to develop their arms in proportion with the rest of their body.
- Those who, for some reason, don't include vertical pulling work (focusing instead on deadlifts and rows) are also likely to need some direct bicep work.
3. Lifters who need a significant amount of arm work for a period of time:
- Those who have a poor mind-muscle connection with their arms will benefit from a good amount of direct work for four to six weeks. When your mind-muscle connection is poor, you'll have a harder time involving these muscles optimally during the compound movements. As a result, they won't get properly stimulated to grow by using only multi-joint lifts.
One of the main benefits of isolation work (for arms or anything else) is that you more easily improve your capacity to contract and feel a certain muscle. It's much easier to concentrate on contracting your biceps if it's the only muscle involved in the exercise than if several other groups are working at the same time and can take over most of the work.
As such, performing frequent direct arm work for 4-6 weeks can be beneficial for future gains by improving your mind-muscle connection with your biceps and/or triceps, making your future training on multi-joint movements more effective.
After that block of direct training, the lifter would need to keep a small amount of direct work to maintain the adaptation and motor skill to contract those muscles properly.
4. Lifters who need a LOT of direct arm work:
- Most competitive bodybuilders will likely need a fair amount of direct arm work in their weekly training. In bodybuilding, you need a distorted perception of optimal arm size because, on stage, arms are one of the major "wow" muscles.
Optimal arm size by bodybuilding standards is actually an overdeveloped level (compared to the rest of the body). I mean, Dorian Yates (pre-biceps tear) still had 20-inch arms but was said to have "small arms" compared to the rest of his body!
Unless you have God-like arm genetics, you'll need a good amount of direct arm work if you want to complete in bodybuilding. And even though direct arm work might not yield huge size benefits when you do plenty of pulling and pressing, every bit counts. In the long run it'll make a significant visual difference.
Over the past 22 years I've trained a lot of competitive athletes: pros (football and hockey), Olympians, top CrossFitters, and amateurs in 28 different sports. We rarely use direct arm work because it's not a great investment of training volume. Despite that lack of direct arm work, their arm size has, for the most part, been proportional to the rest of their body.
In some cases, I'd use one bicep and one tricep exercise per week for certain training phases, if these muscles were obvious weak links in the big compound lifts.
If your goal is to look muscular and athletic, you likely don't need a lot of direct arm work, or any at all. I will concede that if you're after a bodybuilding-type physique, you will likely need a good amount of direct arm work.
Always remember that your body has a limited capacity to handle training stress and grow positively from it. As such, you should invest your training volume where it'll give you the most bang for your buck for what you're trying to accomplish.
- Barbalho M et al. Single joint exercises do not provide benefits in performance and anthropometric changes in recreational bodybuilders. Eur J Sport Sci. 2020 Feb;20(1):72-79.