Back Width vs Thickness: Which One Your Photo Says You Are Missing

Back width and back thickness are two different scores, not two words for the same thing. Width is the Lat Width zone: the V-taper, width from the armpit down. Thickness is the Upper Back zone: thickness and the 3D look from the side. BackMaxx scores both separately, 0–100, from one photo of your back. The lower number is the one you train next, and it already has a four-week block attached to it — V-Taper Sprint for width, Thickness Block for thickness. Most pages on this question end at “you need both.” This one ends at which four weeks you run first.

Width vs thickness in one table

The two zones do not just look different. They are built from different muscles, trained in a different direction, and served by a different slice of the 77-exercise corpus. Width is the narrower problem: 21 movements across six equipment types, and not one of them is a barbell, a dumbbell or a kettlebell. Thickness is the broadest zone in the app: 19 movements across nine equipment types, more than any of the other five zones manage.

That asymmetry is the practical difference between the two. Thickness you can train with whatever is in the room. Width needs something to hang from or pull down against.

What back width actually is

Lat Width is measured at the armpit line and below. Two muscles sit under that score: the Lats (latissimus dorsi) and the Teres Major. The Lats give you the sweep from armpit to waist. Teres Major is the smaller one that matters more than its size suggests — the app describes it as “the small bulge under the armpit that makes the V look wider than it is.”

Both respond to the same direction of travel. The Lats need “a full stretch at the top and a long range. Vertical pulling first, rows second.” Teres Major is hit by “wide-grip pulling and straight-arm work — anything that drives the elbow down and back.”

The corpus backs that up with a hard split. Teres Major is tagged on 17 exercises, and every single one is a pull-up, a chin-up or a pulldown. Not one row in the app tags it. If your entire back routine is rowing, one of the two muscles behind your width score is getting nothing.

That is why width is the more equipment-sensitive of the two. Of the 21 Lat Width movements, six need a pull-up bar, four need a cable stack, two need an assist machine, two need a band, one needs a towel over a bar, and six are bodyweight entries that still assume something overhead. Eight are gym-only. Width is also where the difficulty sits: five of the 21 are rated advanced, against two of 19 on the thickness side. The full breakdown, movement by movement, is in the lat width guide.

What back thickness actually is

Upper Back is the score that reads in profile — how far your back stands off your spine when nobody is looking at you from behind. Three muscles feed it: Rhomboids, Lower Traps and Infraspinatus.

Rhomboids are the bulk of it. They give you “thickness between the blades, and the ridge down the middle,” and they grow “from rowing where you actually squeeze the blades together and pause. Load second, retraction first.” Lower Traps are the ones “almost never trained directly” — Y-raises and prone work at light load beat heavy rowing there. Infraspinatus is the plate under the shoulder blade, and it “trains as a rotator, not a puller.”

Here the corpus split runs the other way. Rhomboids are tagged on 22 exercises, and only two of those sit in Lat Width as their primary zone: Scapular Pull-up and Assisted Pull-up. No pulldown in the app tags Rhomboids at all. Pulldowns and pull-ups do not build the middle of your back, and the exercise data says so directly rather than by implication.

Thickness is also the easier zone to start. Fourteen of the 19 movements are rated beginner, and five of them need no equipment whatsoever: Inverted Row, Prone Y Raise, Prone T Raise, Reverse Snow Angel and Scapular Push-up. Three of those five are done lying face down with light arms, which is why they show up in plans for people who cannot yet hold a row position. The upper back thickness guide has the loading detail.

The one muscle that shows up in both columns

Lats are tagged on 38 of the 77 exercises — more than any other muscle in the app, and more than Rhomboids (22) and Teres Major (17) combined. They appear in all 21 Lat Width movements, in 14 of the 19 Upper Back rows, and in Deadlift, Rack Pull and World’s Greatest Stretch on top of that.

So “training your lats” does not tell you which score is moving. Direction does. A pulldown loads the Lats in a long overhead range and drags Teres Major along with it, which is Lat Width. A bent-over row loads the Lats in a shortened range and drags Rhomboids along with it, which is Upper Back.

This is the reason the two scores can drift apart on someone who trains their back three times a week. Rows keep both muscle groups busy enough that nothing feels neglected, while Teres Major sits at zero volume for months. The photo shows it long before the training log does.

How to tell which one you are missing, from a photo

Take the photo you already take. Back-on, arms down, the same distance and light every time. Width is the outline: how far the silhouette pushes out at the armpit line compared to how far it pulls in at the waist. Thickness is the surface: whether the middle of your back has a ridge and shadow, or reads as one flat plane between the blades.

The trouble with judging it yourself is that the two are hard to separate by eye, because the same photo carries both. Two zone scores separate them for you. The Back Score is the headline number, but it is the six zone scores underneath it that decide what you train, and Lat Width and Upper Back are the two that this page is about.

Read them as a pair, not against the total. The nine rank bands are eight points wide through most of the range — Starter is 38–45, Semi-Pro 46–53, Pro 54–61, and so on. That gives you a clean tie-breaker: if your Lat Width and Upper Back scores land in different bands, that is a real gap and the lower one names your block. If they land in the same band, it is a tie, and you pick on equipment instead.

Per-muscle scores narrow it further. A low Lat Width with decent Lats points at Teres Major, which means the fix is wide-grip and straight-arm work, not more rows. A low Upper Back with decent Rhomboids points at Lower Traps, which means prone Y-raises rather than heavier pulling.

The scores are visual estimates for training motivation, so treat a two-point move between scans as noise and an eight-point move as a band change worth acting on.

The width exercises, by equipment

Twenty-one movements have Lat Width as their primary zone. Sorted by what you need to do them, the shape of the problem is obvious: everything here pulls from overhead, and nothing here is loaded with a free weight in your hands.

Three of the 21 are timed rather than counted, and all three are the low-skill entries: Active Hang, Dead Hang and Child’s Pose. Two more are assisted, which is the only way the app can put a beginner into a vertical pull at all. That is the honest ceiling on width training at home — 13 of the 21 work outside a gym, but almost all of those 13 assume a bar. The full Lat Width list is filterable by equipment if your kit is thinner than that.

The thickness exercises, by equipment

Nineteen movements have Upper Back as their primary zone, spread across nine equipment types — the widest spread of any zone in the app. Fourteen are rated beginner. Nothing here is timed; every entry is counted in reps.

Two of those entries exist purely so a thickness session can happen in an empty apartment: Towel Row, looped around a sturdy anchor, and Doorway Row, gripping the frame and pulling your chest to your hands. There is no equivalent improvisation on the width side, because you cannot fake an overhead anchor with a towel and a door frame.

Notice how the rep ranges split by tool. The barbell entries sit at 5–10 reps and the band, cable and machine entries at 8–15. Rhomboids grow from retraction you can actually hold, so the heavier the tool, the fewer reps the app asks for and the more the pause matters.

Training both without doubling your volume

The mistake is adding a second back day. You do not need one, because most of the corpus already double-dips: 16 of the 21 Lat Width movements carry Upper Back as a secondary zone, and 14 of the 19 Upper Back movements carry Lat Width as a secondary. A barbell row pays into your width score too. A lat pulldown pays into your thickness score too. The payment is just smaller than the one going to the primary zone.

Only ten movements in the whole app pay into one zone and not the other. On the width side: Chin-up, Weighted Chin-up, Assisted Chin-up, Dead Hang and Child’s Pose. On the thickness side: Prone T Raise, Prone Y Raise, Reverse Snow Angel, Scapular Push-up and Chest Supported Row. Those ten are your surgical tools when one score is clearly lagging and you want the volume to land in exactly one place.

The plan builder handles the rest with slot order instead of extra sets. Each session gives the lead zone the first two exercise slots, then one slot each to your next-worst zones, then fills any remaining time with balance work. So a width-led session is not a width-only session — it opens with two vertical pulls and still contains a row.

That is the whole trick. You change what opens the session, not how much you do. Six zones, three sessions a week, and the order decides where the growth goes. The zone guide covers how the other four fit around these two.

V-Taper Sprint vs Thickness Block: which four weeks to run

Both programs are four weeks. Both rotate three lead zones across the week, so two sessions in every three open with the zone you are chasing. Neither requires a pull-up bar, which matters more for the width block than the thickness one.

Read the rotations closely, because they are the actual difference. V-Taper Sprint keeps thickness in the second slot deliberately, “so nothing else slides” — you are not trading your Upper Back score away for four weeks. Thickness Block does the same thing with Rear Delts, picking them up on the way rather than in a separate session, because the same rows that thicken the middle of your back already pass through them.

If the two scores tie inside one rank band, pick on kit. With a bar or a cable stack, run V-Taper Sprint, because width is the harder zone to train later and the equipment is what gates it. With dumbbells, a band, or a door frame and a towel, run Thickness Block, because nine equipment types means the plan will never hand you a movement you cannot do.

So which one comes first?

Whichever score is lower. That is the entire rule, and it is only a usable rule because the two are scored separately in the first place.

Where people go wrong is running the block for the thing they want to look like rather than the thing they are missing. Everyone wants the V-taper, so everyone runs width. If your Upper Back is the number sitting a band lower, four weeks of pulldowns will move your Back Score less than four weeks of rows, and the next scan will say so.

One more case worth naming: if you have not scanned yet, the app defaults its first two training priorities to Lat Width and Upper Back — width and thickness, in that order — because for most untrained backs those are genuinely the two lowest zones. That default is a placeholder for a photo, not a substitute for one. Take the scan, read the two numbers, and let the lower one pick the block.

Re-scan at the end of the four weeks. If the gap closed, run the other block. If the gap held, run the same block again with the second slot swapped. The scores do the arguing so you do not have to.

Find out where your back actually stands

One photo, a Back Score out of 100, six zones and eight muscles ranked — then a plan built on whatever came out lowest.

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