Dumbbell curls vs chin-ups

Dumbell curls are often held on a pedestal for being a good bicep-building exercise, but in fact, the chin-up appears to be considerably better for bicep hypertrophy.

Gentil et al performed a study in 2015 where people were assigned to either a lat pull-down group or a barbell curl group, after 10 weeks of training there was no major difference between the groups in the growth of the biceps and brachialis, in fact, the lat pull-down group had slightly more bicep growth. This reveals that compound movements (movements that work multiple muscles) can grow particular muscles just as well as single joint movements (movements that only require the movement of one joint) when performing either of them alone.

Most exercise routines include both compound movements and single joint movements, instead of either alone, so the question is if single joint movements host any additional benefits when combined with compound movements, luckily Gentil et al performed a different study in 2013, where people were assigned to 1 of 2 groups. Group 1 performed the bench press and lat pull-down, whilst group 2 still performed the bench press and lat pull-down but also performed bicep curls and tricep extensions in addition. Each exercise was performed with 3 sets of 8-12 reps to failure. Fascinatingly after 10 weeks of training, there was no major difference in the growth of the biceps and brachialis between the groups, it only slightly favoured group 2.

I inform you of these 2 studies as the dumbbell curl is a single joint movement for the biceps whilst the chin-up is a compound movement involving the biceps but also the latissimus dorsi, and many muscles in the core. The great thing about the chin-up compared to other compound movements is that the biceps are usually the limiting muscle, while other compound movements such as the row have limiting muscles in the back, such as the latissimus dorsi and trapezius, this inhibits the amount of volume put on the biceps as the set is finished before the biceps are really pushed close enough to failure.

Another benefit of compound movements is that the tension is spread across multiple joints, because if all the tension is put on one joint, muscle fibre recruitment can be inhibited, leading to less muscle growth, this can occur even if you don’t feel the presence of pain.

If you are not yet ready for controlled bodyweight chin-ups (1.5 seconds on the concentric portion, and 3 seconds on the eccentric portion) don’t perform them. You may then go for band-assisted chin-ups, but I wouldn’t recommend them either, as the bottom of the rep is made extremely easy as this is where the bands are storing the most elastic energy and are therefore propelling you upwards, this is also where the biceps are the most stretched and would otherwise cause the most muscle growth, therefore the best option is using an assisted chin-up machine but if you don’t have access to one of these you can perform modified chin-ups, where you sit under a barbell in a smith machine or just in a rack and hang on it just above the ground with a supinated grip letting, your feet stay in contact with the ground to take some load and perform chin-ups this way. You can then progressively overload with this method by placing your feet further and further away from your torso and then potentially placing some weight across your body with your knees closer to your torso to keep the weight stabilised, before performing regular chin-ups then weighted chin-ups.