Illustration of a man flexing his biceps

Both chin-ups and biceps curls are sorely underrated. Chin-ups are easily worthy of being given the same lofty position as the squat, bench press, and deadlift, and yet they’re left out of most strength training programs. According to most strength coaches, curls are even more of a Pariah, but at least most guys who want bigger biceps know to do them.

To be fair, strength training programs aren’t designed to help guys build bigger biceps, and so it makes sense that they aren’t very good at it. But who wouldn’t want bigger biceps?

In this article, let’s compare the chin-up against the curl for biceps growth, and then talk about how to build a biceps bulking routine around them.

Doing Chin-Ups for Biceps Growth

Illustration of a man doing chin-ups

Chin-ups can be a great biceps exercise. In fact, they can even be a great main exercise for our biceps: they’re a big, heavy compound lift that puts our biceps through a large range of motion … sort of, and sometimes.

Chin-ups can be a great exercise for our biceps, but it really depends on how we do them.

For starters, we need to differentiate chin-ups from pull-ups. Chin-ups are done with an underhand or angled grip, whereas pull-ups are done with an overhand or neutral grip, like so:

Illustration of the difference between underhand chin-ups and overhand pull-ups.

With chin-ups, our biceps are in a great position to contribute to the lift. In fact, our hands are in nearly the same position as they are when we’re doing biceps curls. As a result, we’d expect that position to be ideal for biceps growth.

With pull-ups, on the other hand, our hands are rotated away from us, reducing the leverage that our biceps have. In this case, it’s our forearm muscles—our brachialis and brachioradialis—that will be working to flex our arms.

How much of a difference does that make? If we look at the muscle-activation (EMG) research of Bret Contreras, PhD, we see that weighted chin-ups are around 50% better at stimulating our biceps than weighted pull-ups:

  • Chin-up: 107 mean biceps activation, 205 peak
  • Pull-up: 65 mean biceps activation, 145 peak

Chin-ups are much better at engaging our biceps than pull-ups, and thus much better at stimulating growth in them.

The next thing to consider is the range of motion we’re using. As a general rule of thumb, when we’re trying to grow a muscle, we want to train it through a large effective range of motion.

With chin-ups that means starting from a dead hang, with our biceps stretched out to 180 degrees, and then pulling our chests all the way to the bar, contracting our biceps fully, like so:

Illustration of chin-ups done with a full range of motion: from a dead hang and bringing chest to bar.

However, the chin-up is a compound lift, and we’re moving at both the elbows and the shoulders. This complicates things because our biceps attach to our shoulders and forearms. As we flex our arms, our biceps contract, but as we pull our elbows in closer to our torsos, our biceps get longer. So as we pull ourselves up the bar, our biceps are only getting slightly shorter. There isn’t a big change in muscle length.

It isn’t necessarily that bad if a muscle isn’t worked through a large range of motion. What matters more is which part of the range of motion a muscle is worked. The most important part of the range of motion for building muscle is when our muscles are loaded while fully stretched. That doesn’t really happen with the chin-up because raising our hands over our heads shortens out biceps, keeping our biceps from stretching even while we’re in a dead hang.

Now, that doesn’t mean that the chin-up is useless for our biceps. Far from it. As we can see Contreras’ EMG research, our biceps are heavily involved in the chin-up. But it does mean that the biceps curl has at least one advantage over the chin-up: our biceps are worked through a larger range of motion.

Finally, because chin-ups are a compound lift, we’re working several different muscles at once, any of which can be our limiting factor on the lift. Our muscles only grow when we challenge them, and the different muscles involved in the chin-up are all challenged to different degrees. For example, if we fail because our lats aren’t strong enough to bring our chins over the bar, perhaps our biceps are still a few reps away from failure. Maybe our biceps haven’t been challenged enough to provoke a robust hypertrophy response. We could be missing out on quite a bit of biceps growth.

To be clear, chin-ups are quite challenging for our biceps. Most people will get a good biceps stimulus when doing chin-ups. But because our biceps aren’t necessarily our limiting factor, we can’t guarantee that they’re getting a strong enough stimulus to yield maximal growth.

So, to quickly summarise, chin-ups are one of the best lifts for bulking up our entire upper bodies, and they reliably stimulate muscle growth in our biceps as well as in our entire upper backs. However, even though they’re a great lift overall, that doesn’t necessarily mean that they’re ideal for bulking up our biceps in particular.

Doing Curls for Biceps Growth

Biceps curls are certainly the most popular biceps exercise, and they’ve earned it, too: they allow us to work our biceps through a large range of motion with no movement in our shoulder joint, meaning that we get a good biceps stretch at the bottom and a good contraction at the top.

Illustration of a man doing dumbbell biceps curls.
The Dumbbell Biceps Curl.

The sticking point of the biceps curl tends to be in the middle of the range of motion, when our forearms are horizontal. That’s both the hardest part of the lift (peak of the resistance curve) and also where our biceps have the best leverage (peak of our strength curve), flattening the strength curve. Even though we usually fail the lift at that midpoint, having a flatter strength curve allows us to lift more weight.

Because the biceps curl can be loaded fairly heavy, even though it’s a single-joint “isolation” exercise, it’s actually a pretty good lift for strengthening our upper-back muscles and posture. As we’re curling the barbell up, it will try to round our back forward, and so our back muscles will need to hold strong. In that sense, it strengthens our back in the same way that the deadlift does. The heavier biceps curl variations share the most load with our backs, and so the barbell curls and EZ-bar curls tend to work more overall muscle mass.

Illustration of. a man doing a barbell curl with an Ez-bar
The Curl-Bar “EZ-Bar” Curl.

So even though the barbell curl is often thought of as a bodybuilding and aesthetics lift, they’re actually pretty great for our general strength and posture. They’re a great lift all around.

However, as we mentioned above, lifts that load up our muscles when they’re stretched tend to be best for stimulating muscle growth. Problem is, neither the barbell curl nor the chin-up loads our biceps in a stretched position, and so neither has a perfectly ideal strength curve for hypertrophy. That’s where lifts like the preacher curl come in, where the lift is hardest when our biceps are stretched.

Illustration of a man doing a preacher curl for his biceps.
The Dumbbell Preacher Curl.

So, as with chin-ups, there are a number of different ways that we can curl, and each have their own advantages and disadvantages. Here’s what we see in Dr Contreras’ muscle activation research:

  • Dumbbell Curl: 53 mean biceps activation, 118 peak
  • Preacher Curl: 80 mean biceps activation, 145 peak
  • EZ-Bar Curl: 75 mean biceps activation, 146 peak
  • Barbell Curl: 95 mean biceps activation, 138 peak
  • Cheat Curl: 94 mean biceps activation, 136 peak

As an interesting aside, although cheat curls weren’t noticeably better at stimulating biceps growth, they were quite a bit better at stimulating the muscles in our upper backs, making them more of a compound movement.

Anyway, what we’re seeing here is that none of the curl variations are working our biceps as hard as weighted chin-ups:

  • Barbell Curl: 95 mean biceps activation, 138 peak
  • Chin-up: 107 mean biceps activation, 205 peak

The difference is quite stark, too. We’re seeing 50% more peak muscle activation in chin-ups than barbell curls.

Now, this research isn’t perfect, and as we saw with a recent study comparing squats against hip thrusts, sometimes exercises produce more muscle growth despite scoring lower in EMG research. However, when that happens, it’s usually the bigger compound exercises that produce more muscle growth, not the smaller isolation ones.

Plus, one problem with EMG research is that muscle activation levels are higher when our muscles are shortened. That’s a problem because it’s when our muscles are stretched that we stimulate the best muscle growth. As a result, we’d expect lifts like the preacher curl, which are easy at the top (the contracted position) and harder at the bottom (the stretched position), to fare poorly in EMG research, but to produce a ton of biceps growth nonetheless.

Perhaps the biggest advantage to biceps curls, though, is that our biceps are the main muscles being worked, and are thus guaranteed to be our limiting factor. With chin-ups, we could fail because our upper backs aren’t strong enough, which is great for bulking up our upper backs, but our biceps might not be challenged enough to grow. If we take a set of curls to failure, it’s our biceps that will be brought to failure. Curls, then, are perhaps the best way to ensure that we’re working our biceps with a high enough training volume.

So to quickly summarize, there are some notable advantages to curls:

  • Our biceps are worked from a stretched to a contracted position. So even though curls aren’t as heavy as chin-ups, and peak muscle activation levels might not reach quite as high, curls might still yield more biceps growth per rep.
  • Curls are less fatiguing than chin-ups, allowing us to do more sets more quickly, and with less risk of running into recovery issues. This means that curls are usually a better way to add in extra biceps work to our workout routines.
  • Some curl variations, such as preacher curls, load our biceps up heavy in a stretched position, which is ideal for stimulating muscle growth.
  • With curls, our biceps are the limiting factor, and so when we take our sets close to failure, we can rest assured that we’ve challenged our biceps enough to provoke muscle growth.

How to Build Bigger Biceps

Illustration of a man flexing his biceps

If we compare chin-ups and curls for biceps growth, we see that each lift is bringing something special to the table:

  • Chin-Ups stimulate more overall muscle growth throughout our entire bodies, making them a much better compound exercise. They also put the most tension on our biceps and force them to generate the most force, making them the best heavy biceps exercise.
  • Biceps curls guarantee that we bring our biceps close enough to failure to stimulate a maximal amount of muscle growth per set. This makes them the best biceps isolation exercise.
  • Curls work our biceps through a larger effective range of motion and are less tiring per set, allowing us to easily add in complementary biceps work to the end of our workouts without running into fatigue issues.
  • Preacher curls work our biceps hardest in a stretched position, making them uniquely great for building bigger biceps.

As a result, the best way to bulk up your biceps is to focus on getting stronger at chin-ups over time. Treat them like you do your other big compound lifts, and gradually add reps, sets, and weight.

However, to speed that process up, you can also add in biceps curls and preacher curls. They work your biceps in a different way to chin-ups, and the extra volume should yield extra growth.

For example, if we look at this study, we see that adding in biceps curls after lat pulldowns produced nearly 60% more arm growth. We could expect a similar result from adding curls after our chin-ups. And we may expect even better results if we added in preacher curls alongside our chin-ups.

Summary

Overall, chin-ups are better for building muscle in our entire upper bodies, and they’re great for building bigger biceps, especially if we do them with an underhand grip and a full range of motion. Biceps curls, on the other hand, are a more reliable way to specifically bulk up our biceps—especially if we factor in time, energy, and fatigue. Heavy curls also do a decent job of strengthening our upper backs, making them a great overall bulking lift.

To get the best biceps growth, then, it’s best to use chin-ups as our main compound lift and then add curls to the end of our workouts. They both stimulate our biceps in slightly different ways and complement each other well. Interestingly, preacher curls may be the best curl variation to combine with chin-ups, given that their strength curve is so good for biceps hypertrophy.

Cover illustration of the Outlift intermediate bulking program for naturally skinny guys.

If you want a customizable workout program (and full guide) that builds these principles in, then check out our Outlift Intermediate Bulking Program. If you liked this article, you’ll love the full program.

Shane Duquette is the co-founder and creative lead of Outlift, and is the creator of Bony to Beastly and Bony to Bombshell, where he has eight years of experience helping nearly 10,000 naturally skinny people bulk up. He has a degree in Design Theory (BDes) from York University and Sheridan College, and lives in Toronto (Canada) and Cancun (Mexico).

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