Brosiology
Open

Brosiology. Bro science, but it’s physiology.

Joint-aware training for lifters with years under the bar

Lift hard
for decades.

Every one of the 185 exercises is scored on 17 joints and mapped to 66 muscles and heads, so your programs, your swaps and the Program Lab work around the joint you protect. When something hurts mid-workout, say where and keep going.

Score my program Open Brosiology

No account needed, nothing to install, no server holding your log. It runs in your browser, your training stays on your device, and it opens on sample data so you can look around first.

  • Primary
  • Secondary

Anatomy art: Ryan Graves, CC BY 4.0, adapted

Barbell bench press Chest · Front delts · Triceps Shoulder 4/5 · Elbow 3/5 · Wrist 2/5
Exercises
185
Muscles and heads
66
Joints scored
17
Accounts and servers
0

What sets it apart

Logging apps count your sets. Brosiology knows what each set does to your joints, and everything below is built on that map.

01 Joint scores and the Program Lab

Your program, scored joint by joint

Each exercise carries a 0–5 stress score for every joint it loads, with the kind of stress (compression, shear, end range) and a note on why. Mark a shoulder, a knee or one movement of a joint as “go easy” or “avoid”: the generator leaves out what loads it too hard, the library ranks gentler lifts higher and swaps stay kind to it.

The Program Lab scores any program, yours or a generated one: weekly sets per muscle against volume landmarks, push against pull, joint load and high-stress lifts stacked in one session, and session time. Most findings come with a one-tap fix, and every number updates as you change the plan.

  • Each finding says how solid it is: counted, estimated or a judgement call
  • Protect a muscle the same way, by tapping it on the body chart

Program Lab

Upper / lower ×4

4 days · ~62 min
  • solidSide delts: 4 hard sets a week, below the ~8 minimum.Add a set of lateral raises
  • solidShoulder: two high-stress presses in Upper A.Swap incline press for a landmine press
  • judgementChest: nothing loads the pecs in the stretched position.Add 2 sets of dumbbell flyes
Side delts 4 → 7 sets ▲ Shoulder load 38 → 31 ▼ Upper A 66 → 61 min ▼

Example. Fixes change the draft, not your saved program, until you keep them.

02 Mid-workout

Something hurts? Say where, and keep going

Tap Hurts on the workout card, pick the joint or muscle and rate it. Brosiology shows how hard the lift loads that spot and leads with the right move: lighter when it’s mild, a swap to a lift that loads it less, or stop for the day when it’s sharp. Then it checks the rest of today’s workout for anything that loads the same spot.

  • Next time that exercise comes up, the card offers to start 20% lighter
  • Two hurts, or one rated 5 or more, within three weeks offers one-tap protection, and the Lab reworks the program around it

Hurts · set 2 of 4

Right shoulder · rated 5

loads it 4/5
  • SwapDumbbell floor press · shoulder 4 → 2Keeps logged sets
  • Go lighterRemaining sets about 20% lighter
  • SkipMarked skipped, not missed
  • StopEnd the session here

Later today

Incline dumbbell press also loads the shoulder 3/5 SwapLighten

Example. Sharp pain gets a reminder to stop and get it checked.

03 No black box

Shows its working, with sources

The rules are written out in the app with the numbers the code uses: why three sets of bench press count 3 for chest and 1.5 for front delts, the weekly range for each muscle and goal, what each Program Lab finding checks. A “Why?” beside a number opens the rule behind it.

Every exercise map is written to the same rubric, says how well it’s backed and links to its movement family’s evidence notes. A lift is added when it can be mapped properly, and not before.

How it thinks →   The evidence notes →

The evidence behind 185 maps

  • Measured36 backed by a study that tested the lift
  • Consensus115 follow textbook and coaching agreement
  • Estimate34 are our own estimate, and say so
  • Sources112 studies, texts and clinical guidelines, each checked against PubMed or Crossref

Counted from the exercise library and its evidence notes.

What else it does

  • Logbook. Today’s weight and reps filled in, rounded to your plates, with a rest timer.
  • Progression. Hit the top of your rep range and the weight goes up next time.
  • Goals. From your max to your goal: a time range, not a promise, and a 14-week cycle.
  • Progress. Weekly sets per muscle, joint load, lift trends and a muscle heat map.
  • Block check-ins. What moved, what went flat, and a new variation for the flat lifts only.
  • Generator. Full body to bro split, built from your equipment and joint limits.
  • Routine review. Type what you do now (“bench 4×8 185…”) for a review and a three-block plan.
  • Bring your log. Coming from Strong, Hevy or FitNotes? Your history and your routine come with you.
  • 3D animations. Every exercise, with the working muscles painted on.
  • Your own exercises. Same muscle and joint detail as the built-ins.
  • Share codes and backups. A whole program in one code, all your data in one file.
  • Log it after. No phone out? Log the day’s plan after the fact.
  • Offline. Installs to your home screen and works without a signal.
  • Phone, tablet or desktop. On a big screen, a sidebar and two columns: the Library’s list beside the exercise you tap.

How it works

  1. Tell it what you have

    Setup asks your equipment and what you’re training around, then shows what that changed in your program. Mark a muscle to protect on You. Tap Start fresh to leave the sample data.

  2. Score your program

    On Plan, type in your routine, build it or generate one, and open it in the Program Lab.

  3. Train and log

    On Train, tap Done as you go, and Hurts if something flares.

  4. Set a goal

    On Goals, enter where you are and where you want to be, and build the 14-week plan.

  5. Check in weekly

    On Progress, read volume, joint load and suggestions against your projection.

What’s new

  1. Tap an exercise to see what it is. Tapping a name in a program shows its motion, muscles and joint loads, then the closest swaps, the same move on other kit first.
  2. Lower-back loads, re-checked. Every exercise’s lower-back rating was checked against the spine-load studies and plain mechanics. The hip thrust now counts as real lower-back work: a study found the lower back works about as hard as in a deadlift to hold the trunk level off the bench. Shrugs, dumbbell lunges and split squats, the hack squat and the standing calf raise now show the load they send down the spine, and the sumo deadlift is rated only a little easier on the back than conventional. The evidence notes say what the ratings are for: picking kinder lifts while your back is sore, not a list of lifts to fear.
  3. Fixed: narrow phones scrolling sideways. Setup’s last step and the Program Lab fit the screen again: no sideways scrolling, and no scrolling past the end on phones with a notch.

Everything that’s changed →

Questions

I already use a logging app. Why this?

Keep it if you like it. Brosiology does what a logbook doesn’t: joint scores, program analysis and a session that adjusts when something hurts. It logs too. Coming from Strong, Hevy or FitNotes? Bring your log: its CSV export comes in as your history, and yours exports as CSV, so nothing is locked in.

Do I need an account?

No. Open it and start. An optional account may come later for syncing between devices; you won’t need one to train.

Where is my data kept?

In your browser, on your device; nothing goes to a server. Clearing site data erases it, so back up from You → Data now and then. On iPhone, the Home Screen app keeps its own data, separate from Safari. The privacy page has the details.

Where do the joint scores come from?

Every map is written to one rubric, checked by the test suite and graded measured, consensus or estimate. They’re programming estimates, not medical findings.

Does it work on my phone?

Yes. It’s built for a phone first, installs to your home screen and works offline.

How accurate are the goal timelines?

Reasonable within one 14-week cycle and rough past six months, so the app shows a range and re-projects after every cycle.

Is this medical advice?

No. It’s built on published research and clinical guidelines, and the evidence notes show the sources, but joint stress ratings are programming estimates. If something hurts, stop and get it checked.

Start with the program you already run.

Score my program Open Brosiology