Pull-ups and chin-ups, what's the difference between the two, and more importantly, is one better than the other? You've likely already had this discussion with another person, or at least heard of the topic, where one pulling technique is pinned against another. The problem here is that most people miss out on the small details in these debates, leaving a lot of key points out. This is why I decided to investigate the whole "pull-ups vs chin-ups" argument at Ballamazingly.com and provide my findings here.
The classic difference that everyone brings up is how each exercise is executed. More specifically:
Chin-ups are done with an underhand grip and are often narrower in grip width.
Pull-ups are done with an overhand grip and are often wider in grip width.
Ultimately, this is the key distinction that separates each of the pulling movements, but the conversation usually stops at this point as to how exactly these variances make a difference in how you develop your body.
With pull-ups, the overhand grip places your arm in a pronated position which puts your biceps in a mechanically disadvantaged position. To continue the pull-up motion, you have to derive your leading force from somewhere, and this is where your back gets involved. The latissimus dorsi, or lats, become the leading muscle that gets you over the bar, with the biceps contributing less to the overall exercise.
This means that as your biceps are slowly removed from the equation, the lats become isolated and are that much more used due to the added pressure. Not to mention that grip width also determines the level of engagement from the biceps, with a wider grip leading to less engagement from the biceps, and requiring more from the lats.
For this reason, pull-ups largely focus on the back and lats, leaving a person with a wider torso and often stockier frame.
In contrast, chin-ups use the pronated grip which places your arm in a supinated position and puts the biceps in a mechanically advantaged position. Couple that with a narrower grip which leads to further involvement of the biceps, and you can start to piece together a pattern.
The purpose each variation serves sways between building a bigger back or a bigger set of biceps, much like a pendulum, and your selection of both grip and grip width is what will determine which muscle group you build on more. Namely, there are five variations; these include:
Shoulder-width grip Pull-ups
Shoulder-width grip Chin-ups
Wide grip Pull-ups
Narrow grip Chin-ups
Neutral-grip
The neutral-grip is a unique case, as it involves the hands facing each other, leaving you a semi-pronated semi-supinated position. This actually makes it the easiest variation, as the demand of the exercise gets separated roughly evenly between the arms and back, leaving them both equally trained, though nowhere near as developed as the other two options.
Chin-ups follow in difficulty since most people usually have more dominant strength in the arms than in the back, making pull-ups by far the hardest pulling variation. Now you know why pull-ups are almost always included in every fitness exam; they not only serve as a great indicator of relative strength but also provide a real challenge for those inexperienced with the movement.
In fact, I would argue that pull-ups are by far one of the most challenging exercises, which makes it a great tool for developing your mental toughness, as with most exercises. It sure isn't a wall sit, but the difficulty it brings can definitely push you to handle more discomfort.
Now, here's where I want to include some more unique information, specifically, recommendations of what not to do with these exercises. These pointers often get left out, but putting them to use can help you to drastically get more out of your training sessions.
Don't extremely perform each exercise -
What I mean here is that while the width of your grip can be adjusted to better suit your goals, don't use an overly wide or overly narrow grip, regardless of the variation you choose. The reason why is simple; a grip that is too wide or too narrow is likely going to get you injured, and particularly for wide-grips, limit your range of motion, thereby limiting your gains.
Trust me when I say that while adjusting the width of your grip can help, the difference in muscle recruit is not all that notable, especially when compared to the standard shoulder-width grip. For this reason, I recommend you stick to the traditional way of doing each variation.
This also applies to strange or potentially dangerous variations such as the behind the head pull-up. Although it may have some benefits, such as further isolation and development of the lats, the stress it places on the neck and shoulders pose a great enough threat to your body to warrant not being used.
You don't need to use only one variation -
You may be thinking to yourself "All right, guess I'll just stick to pull-ups/chin-ups" but honestly, if you want to get the most out of your sessions, then alternate between the two, and all three if possible (neutral grip). This helps to not only add variety to your workout session but also helps alleviate stress from certain muscle groups and allow them time to recuperate by having them used to a lesser.
Now I realize this may seem counterintuitive, especially since I just went into detail on how each exercise differs and the impact each one can have on your body. Although true, you have to remember that regardless of the choice you make, the same muscles are still used to complete the motion, only to different lengths.
Because they're all pulling movements, they still involve the biceps, triceps, lats, pecs, and shoulders, and in the end, you can benefit a lot more from incorporating all these exercises into your training regimen and using them in moderation.
On a side note, I will add that this point can be applied to practically all other exercises you perform; it's a good idea to alternate between variations and swap the days in which you use them per week to always keep your body adapting.