Focus program
Thickness Block: four weeks of rows in the lead slot
Rows go first. Upper Back opens two of the three sessions and Rear Delts opens the third, and what the block is after shows in a side-on photo rather than a back shot.
What is Thickness Block: four weeks of rows in the lead slot?
Thickness Block is a four-week BackMaxx focus block that leads two of its three sessions with Upper Back and the third with Rear Delts. Horizontal pulling opens every lead session, with the shoulder blades retracting before the load matters. The change it targets reads in profile rather than from directly behind.
| Length | 4 weeks |
|---|---|
| Leads with | Upper Back · Rear Delts |
| Equipment | Adapts to whatever you have |
| Where | Home or gym |
| In the app | Start it from the Train tab; your scan still fills the rest of each session |
What this block means by thickness
Depth off the ribcage, measured from the side. The Upper Back zone payoff in the app puts it as thickness and the 3D look from the side, and that is the only view where the difference is obvious. From directly behind, a thick back and a wide back can post similar photos.
Three muscles carry it. The Rhomboids fill the span between the shoulder blades and build the ridge down the middle. The Lower Traps pull the blades down and in. The Infraspinatus sits under the blade as a small plate and adds the separation you notice in good light.
Nineteen movements in the corpus are tagged Upper Back as their primary zone, and most of them are rows. The block leans on that pool hard for four weeks.
Who should run Thickness Block
Take it when Upper Back is your lowest zone, or when Lat Width and Upper Back scored close but your side-on photos look flat while your back shots look fine. That combination is the specific case this block was built for.
Leave it alone if your Lats are the lagging piece. Rows feel like upper-back work and are not only that — Lats are the most-tagged muscle in the whole corpus, on 38 of the 77 movements, and they take a real share of every heavy row. Four weeks of rowing with lats already behind tends to widen you slightly and thicken you less than the block promises.
One more disqualifier: if you row with the elbow travelling and the shoulder blade parked, the block cannot help. Retraction is the requirement, not the bonus.
How a lead session is built
Upper Back gets the first two slots of the main block: the heaviest horizontal pull, then a second rowing angle so the blades get loaded from more than one direction. Everything the scan flagged behind that fills slots three and up.
The warm-up is not generic here. An Upper Back lead pulls its activation from Band Pull-Apart, Scapular Push-up, Reverse Snow Angel and Prone T Raise — four movements that ask the shoulder blades to move with almost no load on them. Treat them as a rehearsal for the retraction you are about to do under weight, because that is the job they are in the session to do.
The Rhomboids training note in the app is blunt about the priority: load second, retraction first. A row where you squeeze the blades together and pause is a different exercise from the same row moved faster.
Which rows the block draws from
| Row | Default | What it puts the emphasis on |
|---|---|---|
| Chest Supported Row | 3 x 8–12 | The only row in the corpus tagging Rhomboids, Lower Traps and Rear Delts together. The pad removes your torso from the equation. |
| Seated Cable Row | 3 x 10–12 | Constant tension through the whole pull, and the easiest place to hold a squeeze at the back. |
| Barbell Row | 3 x 6–10 | The heaviest option. Carries Lat Width and Lower Back as secondary zones, so it taxes more than the mid-back. |
| Pendlay Row | 3 x 5–8 | The only row tagging the Erectors directly. Advanced, and every rep restarts from the floor. |
| T-Bar Row | 3 x 8–10 | A neutral grip and a short, thick range. Blades in, elbows past the ribs. |
| Inverted Row | 3 x 8–12 | Bodyweight, so the load is set by your foot position rather than a plate. |
| One-Arm Dumbbell Row | 3 x 8–12 | One side at a time, with a longer range than any bilateral row allows. |
Something falls out of that list that the block never advertises. Eight movements in the corpus touch Symmetry as a secondary zone, and four of them are single-arm rows with Upper Back as their primary: One-Arm Dumbbell Row, Single-Arm Cable Row, Kettlebell Single-Arm Row and Meadows Row. A rowing block that keeps rotating its angles quietly gives the Symmetry zone more attention than any other block in the app.
Why the third session hands over to Rear Delts
Because the mid-back and the rear shoulder finish the same silhouette from the side, and because rowing alone under-serves the smaller muscle. Session C leads with Rear Delts, which is how the block picks them up on the way rather than scheduling a separate week for them.
That session also puts the prone work where it belongs. Lower Traps respond better to light Y-raises and prone holds than to heavy rowing, so the third session covers what the two rowing sessions cannot reach at load.
At two sessions a week the Rear Delts lead never comes up in the rotation. If that is your schedule, run the block knowing it is a pure rowing month, or move to three sessions for the four weeks.
What four weeks changes, and how to check
Photograph your back from behind for the scan, then take a second shot from the side for yourself. The scan scores the view it is given, and the side view is where thickness argues its case.
Look for three things at the end. The ridge either side of the spine between the blades. The blades themselves sitting flatter against the ribcage rather than standing off it. A back that no longer disappears when you turn 90 degrees.
Two zones usually move together on the scan. Upper Back is the target, and Rear Delts often follow because the third session led with them and half the rows tag them anyway.
What to run after Thickness Block
Read the new scan, then pick against it. If Lat Width is now the lowest, four weeks of width work makes the depth you just built look like a shape rather than a slab, and the width versus thickness comparison lays out why the two get judged from different angles.
If Traps and Rear Delts came back as the pair at the bottom, take the shorter block next. Three weeks is enough for two small zones, and the base you spent a month building stays in behind the lead.
Do not run a second rowing month straight away. The pool is 19 deep and you will have seen most of the good ones, and the zones you parked in slot four start reading like it. Read the upper-back thickness guide before you decide, because the answer is sometimes to stop blocking and just row heavier for a while.
The movements this block leans on
Frequently asked questions
What is the Thickness Block program?
A four-week BackMaxx focus block that puts Upper Back in the lead slot of two sessions out of three and Rear Delts in the third. Horizontal pulling opens every lead session, taking the first two positions of the main block, and your scan’s other priorities fill the slots behind it.
Do rows build a thicker back than pull-ups?
For the span between the shoulder blades, yes. A row lets the elbow travel behind the ribs, which is where the Rhomboids and Lower Traps shorten. A vertical pull moves the arm overhead to down, which builds the width of the line from armpit to waist instead. Different jobs, different views.
How many sets of rows per session does the block use?
It fills slots rather than prescribing a set total. The lead compound and the second rowing angle both come from the Upper Back pool, at each movement’s default sets, and the lead compound goes to four sets on a 60-minute session for intermediate and advanced lifters.
Why does the block include Rear Delts at all?
Because rowing alone under-serves them and they finish the same profile. Only one row in the corpus, the Chest Supported Row, tags Rear Delts alongside the Rhomboids and Lower Traps, so the third session leads with them directly rather than hoping the rows cover it.
Can Thickness Block be run at home?
Yes. Five of the 19 Upper Back movements are bodyweight, led by the Inverted Row, and the pool also holds a Banded Row, a Towel Row and a Doorway Row. The lead slot will be lighter than a barbell session, so expect to earn the depth through range and pauses instead.
Run Thickness Block: four weeks of rows in the lead slot in BackMaxx
Scan your back, start the block, and every session opens with upper back and rear delts while your scan fills the rest of the week.
Download on theApp Store Download on the App StoreFree to download. iPhone, iOS 26 or later.