One Arm Chin-Up
Also works: Biceps · Forearms · Lats
Assisted work toward pulling your bodyweight with a single arm: one hand on the bar, the other holding a towel looped over it so the assisting arm can take progressively less of the load. This is a multi-year skill, and the towel hand is what makes it trainable rather than a party trick you either have or do not.
Own the movement
Set up first, then execute. Every cue below is something you can check on your next set.
Before the first rep
- Loop a towel over the bar next to your working hand and grip it with the other, palm facing you on the bar.
- Set your towel hand high for more assistance, lower down the towel as you get stronger.
- Lean your torso back about 30 degrees with your chest up and a slight arch in your lower back.
- Brace your abs and squeeze your glutes before you leave the hang — the trunk holds you square, not the bar.
- Chalk up. Failing on grip in this position means dropping from a dead hang under rotation.
Every rep
Breathing & tempo — One big breath at the hang, held through the whole rep, exhaled at the top. Explosive intent on the way up even when the bar moves slowly; four to five seconds down.
Before you load it
- This loads the elbow tendons harder than any other bodyweight pull. If the inside of the elbow aches for more than a day after a session, cut the volume in half and add heavy biceps work.
- Test the towel's grip on the bar before hanging your bodyweight from it, and never use a frayed or thin towel that can slip through the hand.
Sets, reps & load
Where to start, and what to change when it stops being hard.
Bodyweight is the load and the towel is the dial. A reasonable entry point is fifteen strict two-arm chin-ups or five chin-ups with 25% of bodyweight added; below that, spend the year on those instead. Progress by sliding the towel hand 5 cm lower once you hit three clean reps per side, never by adding reps at the same assistance.
What goes wrong
The errors that show up most often, and the cue that fixes each one.
Start with your towel hand right up at the bar and take one small step down the towel every two weeks. Progress the assistance in centimetres, not in attempts.
Drive the free-side hip down and hold your sternum square to the bar. If you cannot hold square, move the towel hand up until you can.
Put it first, after the warm-up, before anything else. Three minutes of rest between sets. Fatigued attempts build elbow tendinopathy, not one-arm chin-ups.
Keep every set at one to three reps and progress by lowering the towel hand. A set of eight assisted reps is a different exercise and does not transfer.
Why bother
A single arm pulling your whole bodyweight is roughly double the demand of a normal chin-up on that lat, biceps and forearm, and far more than double on the trunk. The side you are not pulling with has to resist the rotation and lateral bend the load creates, so your obliques end up working as hard as your back.
The towel is a continuously adjustable dial. Grip it high, close to the bar, and the assisting arm takes most of the work; slide your hand further down the towel and the leverage drops until it is barely steadying you. That gradient is what turns an all-or-nothing feat into something you can progress week by week.
Where it fits
First movement of a pull day, on completely fresh arms, twice a week at most. Sets of one to three reps per side with three minutes between them. Back it up with heavy two-arm chins and direct elbow work — most people who stall on this stall on the biceps and the connective tissue around the elbow, not the lat.
If this one isn't it
No kit, too hard, or too easy — here's where to go instead.
Asked and answered
How long does it take to get a true one-arm chin-up?
Years for most people, and plenty of trained lifters never get one. Bodyweight matters enormously: at 65 kg it is a hard but realistic goal, at 95 kg it is a very different proposition regardless of how strong you are. Treat the assisted version as the training tool it is, not as a failed attempt at the real thing.
Towel, rings or a band for the assistance?
A towel, because it is the only option that is continuously adjustable and gets weaker the further you slide down it. A band gives its most help at the bottom where you need it least, and rings for the free hand let you cheat with a second full pull without noticing.
Should I train the negative on its own?
Yes, and it may be the most productive part. Get to the top with a jump or with the towel hand high, let go, and lower with one arm over six to eight seconds. Two or three of those per side after your regular sets builds the top-range strength that assisted concentrics do not.
Why does my elbow hurt after training this?
Because the biceps and the common flexor tendon are taking close to double their usual load with none of the gradual build-up the lat gets. Back off the assistance level, cut to two sessions a week with three days between them, and add slow, heavy curls to build tendon tolerance directly.