Algorithm changelog
Our scoring isn't set in stone. As we learn more — from research and from real training data — we improve how fitn3s rates your fitness and builds your workouts. Here's every meaningful change, newest first, so you can see exactly why your numbers look the way they do.
The engine behind your per-body-part levels. Each version is numbered, so your profile chart always knows which formula drew each point.
One off day can't rewrite your level anymore
A single weaker session on one exercise used to be able to drag its whole body part down — log a great set one week and a tired, lighter one the next, and your level would read the tired one. v9 reads each exercise from the best of your last three sessions on it, so an off day gets absorbed instead of rewriting your score. A real decline still shows — it just takes more than one lighter session to register.
Technically: Each contributing exercise's implied level is now the maximum across its 3 most recent successful logs (CAPACITY_RECENT_N), not just the newest one, before it feeds the body-part's 75th-percentile capacity estimate.
Fairer levels that one exercise can't fool
Your level for each body part used to lean too heavily on your single strongest exercise — so one standout movement (or an over-generous one) could inflate a whole area. v8 reads across more of your exercises before settling on a level, and we recalibrated 19 movements so the same level means the same achievement whether you're doing push-ups or holding a wall handstand.
Technically: The capacity estimate now interpolates the 75th percentile of your demonstrated levels instead of an index that collapsed to your single best on four or fewer exercises; your fitness-test baseline fades per distinct exercise you train (not per log); and 19 calibration curves were re-anchored so no movement certifies an elite level too cheaply.
A custom difficulty curve for every exercise
We gave each exercise its own research-based 'reps → level' curve, replacing a one-size-fits-all conversion. So 30 push-ups, a two-minute plank and 10 pistol squats each translate to a fair level for that specific movement — a skill move counts for more than a high-rep accessory move.
Technically: Per-exercise calibration curves replaced the shared reference-curve-plus-difficulty-offset model. Curves were sourced from a structured research pass across the whole exercise catalog.
Training stopped dragging your levels down
Early on, doing lots of easy, high-rep finisher work could actually pull a body-part level down. v6 started estimating each area from a high point of what you've demonstrated rather than the average — so light accessory work no longer hides your real capacity.
Technically: Switched to a 75th-percentile capacity estimator over your demonstrated levels, so easy outliers no longer weight the score down.
The first Body Fitness Profile
The launch of per-body-part levels. We blended your five-minute fitness test with your logged performance to give every muscle group its own 1–40 level and an honest confidence label, plus a monthly history line so you can see each zone improving.
Technically: A fitness-test prior blended with the levels implied by your logs, per-exercise starting-target seeding, and a level floor that gates which exercises appear in your plan.
Getting the scale right
Before the public profile launched, we tuned the underlying scoring and scale until levels lined up with real-world benchmarks. For a short while the scale even topped out at level 25 before the full 1–40 range arrived.
Technically: Pre-launch iterations on the score formula, its weights and denominator; capped at level 25 until the full 1–40 range landed in v5.
Notable changes to how your daily session is built and adapted. These aren't version-numbered — here are the highlights, newest first. For the full picture, see how the workout algorithm works.
Targets that adapt both ways — and a much higher ceiling
August 2026Your personal target now watches your recent sessions and moves in either direction: keep clearing it and it rises, fall short for a while and it eases back down instead of leaving you stuck on a number you can't hit. We also raised the ceiling on most exercises — many were capped well below what the full 40-level scale allows, so there's a lot more room to climb than there used to be.
Fuller body-part coverage, full-body exercises are back
August 2026Daily plans now reliably cover every body part you've asked to train, instead of quietly dropping the last couple when the day filled up early. Full-body exercises are also back in rotation for anyone who had all areas selected.
Bonus rounds match a stretch day
August 2026Start a bonus round on a stretch/recovery day and you'll get more stretches, not a surprise strength exercise.
“Tricep Dips” became “Bench Dips”
June 2026We renamed Tricep Dips to Bench Dips and re-anchored its difficulty curve to the chair/bench version most people actually do — feet on the floor, legs sharing the load — so a set of bench dips no longer reads as an elite-level feat. Your history, streaks and badges for this exercise carry over unchanged.
Soft vs strict focus areas
June 2026Pick 'Mostly these' to get a plan led by your chosen areas — like Legs, Bums & Tums — with a little full-body variety mixed in, instead of only those areas.
Smarter starting targets + re-test recalibration
June 2026New exercises now start at a difficulty seeded from your Body Fitness Profile, and after you re-take the fitness test we suggest target adjustments wherever your level has moved.
Knee push-ups in the fitness test
June 2026Take the push-up test on your knees and we convert the result to a full-push-up equivalent, so beginners still get an accurate starting level.
Mixed and Focused workout styles
June 2026Choose Mixed (a bit of everything, every day) or Focused (a two-day upper / lower-&-core rotation that gives each region a rest day before it comes round again).
Travel-proof streaks
June 2026Your day boundary now follows your device's time zone automatically, so crossing time zones no longer resets your daily plan or breaks your streak.
Difficulty gate & progressive overload
FoundationalExercises unlock at your tested level so nothing is wildly too hard, and your targets rise automatically once you beat them three sessions in a row.
See your own Body Fitness Profile
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