The short answer
Hang from a bar and the only thing separating these two exercises is the way your palms face. That changes how the elbow bends and how the upper arm travels, which changes how much help the lats get from the arms, but not which muscle leads. The lats, the broad muscles down the sides of your back, are the main movers either way.
If you cannot do either yet, the grip question can wait: the first pull-up guide covers the hangs, holds and slow lowering that lead to a first rep. Where both exercises sit in a week of rows, pulls and hinges is set out in the back training guide.
Side by side
| What differs | Chin-up | Pull-up |
|---|---|---|
| Grip | Underhand, palms facing you | Overhand, palms facing away |
| Usual hand width | About shoulder width | Shoulder width to a little wider |
| Elbow path | Elbows come down in front of the body | Elbows come down and out to the sides |
| Main mover | Lats | Lats |
| Arms and chest | More help from the biceps and chest | Less help from the biceps |
| Shoulder-blade muscles | Working, a little less | More work for the lower trapezius |
| How hard it feels | Easier for most people | Harder for most people |
| Common complaint | Underhand grip bothers some wrists and inner elbows | Overhand grip bothers some shoulders |
What a 2010 study measured
Researchers at the Mayo Clinic recorded muscle activity in 25 young adults, 21 men and 4 women, during pull-ups, chin-ups and a version with rotating handles. The lats were the most active muscle measured in all three. The biceps and the chest were significantly more active in the chin-up, while the lower trapezius, which draws the shoulder blades down, was more active in the pull-up. The rotating handles made no difference, and the elbows bent through a slightly larger range in the chin-up.
- In practice, the chin-up shares the work with the arms and chest, one likely reason it tends to feel easier.
- The pull-up leans more on the shoulder-blade muscles, which may help explain why someone who manages plenty of chin-ups can still find pull-ups much harder.
- The limits: one small study, mostly of men, measuring activity in a single session rather than growth over months. It shows how the work is shared, not which exercise builds more muscle.
Which is harder, and which builds more
Most people can do more chin-ups than pull-ups, and the underhand grip is where many people get their first rep. That is a common coaching observation rather than a study result, and there are exceptions, often people whose elbows or wrists dislike the underhand position.
For building the back, neither has been shown to beat the other. Both load the lats heavily through a long range, and what drives growth is hard sets taken close to failure, enough of them each week, and a load that rises over time. Choose the chin-up if you also want the biceps to work hard; choose the pull-up if you want the shoulder-blade muscles to do more.
Where the neutral grip fits
A neutral grip, palms facing each other on parallel handles, sits between the two. Many people find it the most comfortable on the shoulders, wrists and elbows, and its difficulty usually falls somewhere between the chin-up and the pull-up. It needs a bar with parallel handles or a V-handle hooked securely over a bar, so check what your gym has. On a cable station, a neutral handle on the lat pulldown lets you practise the same grip at any load.
When to choose each
Choose the chin-up when:
- You are working towards your first bodyweight pull, or want more reps in each set.
- You want the biceps to work hard alongside the back, for example on a short upper-body day.
- The overhand grip bothers the front of your shoulder.
Choose the pull-up when:
- You can already do several chin-ups and want a harder version without adding weight.
- You want more work for the muscles that draw the shoulder blades down, or your sport, such as climbing, pulls overhand.
- The underhand grip strains your wrists or the inside of your elbows.
Using both in one programme
Rotating the two works better than choosing once. Three simple ways to do it:
| Approach | How it works | Who it suits |
|---|---|---|
| Alternate by session | Chin-ups on your first upper-body day, pull-ups on the second, 3–4 sets each, stopping one or two reps short of failure | Anyone who can do at least three or four of each |
| Alternate by block | Four to six weeks on one grip, then four to six on the other, logging reps | People who like watching one number climb |
| Chin-ups now, pull-ups later | Build to sets of six to eight chin-ups, then start adding pull-up sets | People who have only just got their first rep |
Once sets of ten or more feel easy, add load with a dipping belt or slow the lowering to three seconds. If either grip causes pain in the shoulder, elbow or wrist, stop and have it checked by a doctor or physiotherapist.
Chin-ups and pull-ups at RPM
RPM's floor photos show multi-station cable towers with a pulldown seat and thigh pads, where you can train both grips on the pulldown, but they do not confirm a pull-up bar or an assisted pull-up machine. Ask the team on your free guided tour where you could hang and pull. A coach in a personal training session can watch your reps and help you pick the grip that suits your shoulders.
Sources
Questions, answered.
Which is better for the lats?
Both train the lats hard; the 2010 study found them the most active muscle in each version. Choose by which other muscles you want working and which grip you can control through a full range.
Can chin-ups replace bicep curls?
For many people the biceps work in chin-ups is plenty. If arm size is a priority, a few sets of bicep curls add direct work on top, and the biceps guide shows how much.
Chin-up or lat pulldown?
The pulldown lets you set the load, so it trains the same direction of pull before you can lift your bodyweight, or adds volume afterwards. An underhand grip on the pulldown mimics the chin-up. The lat pulldown vs pull-up comparison goes into detail.
How wide should my grip be on pull-ups?
A little wider than your shoulders is the usual starting point. Research on the pulldown found similar lat activity across a range of grip widths, so there is little reason to go very wide, and many people find very wide grips hard on the shoulders.
Do I need a chin-up before I can do a pull-up?
No, but it is the usual order, because the underhand grip is easier for most people. If your first rep comes on a neutral grip or a pull-up instead, that counts just as much.