The Science Behind the Sculpt Credit Score

Did you do the sessions you planned?

Where we draw the line: 80% of planned sessions scores well. You do not need 100%.

Across exercise programmes that report attendance, average adherence is 80% of prescribed sessions (range 60–98%), and 80% is the cutoff trials conventionally use to define “high adherence.” Where outcomes have been split by attendance, the line falls near 75%.

Why this is graded Convention: 80% is the field’s working definition and its observed average. It is not a proven cliff, and no study has established one. We use it because it is the best-supported convention available, not because it is a finding.

Training more than planned earns nothing extra here. Extra work raises fatigue, and fatigue is priced by Recovery below.

Sessions, not weeks. A session counts the day you train it, and a planned session only counts as missed once the days left in its week can no longer fit it. Nothing waits for Sunday night, so an open week earns partial credit and no single day swings your rate by more than a session or two.

New accounts ease in. Your first sessions are thin evidence, so the rate starts pulled toward the 80% bar and that pull fades out as real sessions accumulate, reaching your raw rate at 16 judged sessions. Missing your first planned session reads as 75%, not zero.

Are you moving toward your goal, at a rate that is safe?

Where we draw the line: Full credit for real movement: 0.25% of bodyweight a week when losing, 0.1% when gaining. Credit falls away above 1.0% and 0.5%.

This is the factor where going too fast counts against you, and it is the best-evidenced number on this page.

Losing weight. Garthe and colleagues randomised 24 elite athletes to lose either 0.7% or 1.4% of bodyweight per week while strength training four times a week. The slower group gained 2.1% lean body mass; the faster group gained none (−0.2%). Same weight off the scale, very different bodies underneath.

Gaining weight, where the ceiling is much tighter. In a separate Garthe trial, 39 elite athletes went through a gaining phase. The faster group put on 0.38% of bodyweight per week and the slower group 0.16%. Muscle gain was similar between them, but the faster group gained roughly five times the fat (1.1 kg vs 0.2 kg). Past a slow rate, extra weight is mostly fat. The published recommendation for lifters in a gaining phase is 0.25 to 0.5% of bodyweight a week, so 0.5% is our ceiling, and anything faster counts as too fast.

How it is scored. Your target date plays no part. We grade the direction and the rate you are actually moving against the same band for everyone, so a deliberately slow plan is never marked down for being gentle and an ambitious date never makes you fail. Full credit starts at 0.25% of bodyweight a week when losing and 0.1% when gaining, the floor below which a phase is not really a phase, and credit falls proportionally from there to nothing at no movement at all. Moving the wrong way earns none. Reaching your target restores full credit as you close on it, so arriving and holding is not scored as a stall.

Going too fast is the other way to lose credit here, and only bodyweight goals can. Past 1.0% a week losing or 0.5% gaining, credit falls away and reaches zero at twice those rates. That falloff is our convention.

Strength goals. A goal to lift more is judged on that lift's estimated one-rep max, taken from your best set in each session. Any steady climb earns full credit from 0.1% of your one-rep max a week, and unlike bodyweight, climbing faster is never penalised. There is no published safe ceiling for getting stronger, so that is our convention. Endurance goals are not scored yet.

How we read your rate. Pace fits a line through every reading you have logged since the goal started, within the last six weeks, not a straight line from where you started to where you are today. Readings count in full for three weeks and fade out over the next three. A reading that disagrees sharply with the rest, the kind you get from one heavy morning after a week away from the scale, counts for proportionally less, while two or three that agree still move your rate properly.

We only trust the line as far as it deserves. A rate fitted through a handful of noisy readings is held close to neutral, and it earns its full effect on your score as the readings pile up and agree with each other. A new goal therefore starts neutral rather than at zero, and a goal you have not weighed or trained in three weeks drifts back to neutral instead of holding an old verdict.

Your rate needs at least five readings across the last four weeks, spread over a week or more, before it is calculated at all. Until then the goal sits at the neutral value rather than counting as zero.

Are you training inside what your body can absorb?

Where we draw the line: Starting a session on a muscle group you train directly, while it is below 33% freshness, costs you. Training often does not.

Every session leaves fatigue in the muscles it worked, and that fatigue fades. We model it as a decaying curve rather than a fixed rest period.

How long fatigue lasts depends on how hard you trained. Morán-Navarro and colleagues found that sets stopped well short of failure were recovered within about six hours, while sets taken to failure needed 48 to 72 hours. So after each exercise we ask how many more reps you had left, and fatigue from work taken to failure clears several times slower than fatigue from easy work.

Training a muscle group often is never penalised. When total weekly volume is the same, training a muscle more often grows and strengthens it at least as well as training it once a week. Only starting a session on a muscle that is already fatigued counts against you, and only for the muscles the session trains directly. Muscles that assist, like your core bracing during a squat, add half their share of fatigue but never make a session count as a miss on their own.

A bad session leaves gradually. Each session counts in full for three weeks, then fades to nothing over the last week of the window, so one fatigued start costs you less every day rather than dropping off your record overnight. And because three sessions in a month say very little about how you recover, a thin record is held near neutral until about eight sessions have been judged.

Why this is graded Moderate: the recovery times come from controlled trials, but the exact speeds we clear fatigue at, the 33% line and the half share for assisting muscles are our conventions. They are starting values, and we will calibrate them against how people actually perform in their next session. Research also shows recovery speeds up as you get fitter; we do not model that yet.

Are you eating for the goal you set?

Where we draw the line: Judged on weekly averages, not single days. Three good weeks out of four scores well.

We score weeks, not days, and there are two reasons.

The first is that a weekly average is what actually drives the outcome. Eating 1,800 one day and 2,800 the next averages out to exactly your target, and penalising that would be penalising nothing.

The second is measurement. Under FDA rules a pack can legally contain up to 20% more calories than its label says, and when checked against laboratory methods people under-report their calories by around 12 to 20% and their protein by 11 to 15%. Scoring a single day against a tight target would be scoring noise. Averaging a week shrinks that error instead of compounding it.

Calories are judged against the same target and the same on-track range your food screen shows, including any calories you add back for activity. The score is never stricter than your own food screen.

Why three weeks out of four, and not four. Conlin and colleagues randomised resistance-trained lifters to a flexible or a rigid diet through a ten-week deficit and found equivalent fat loss. Rigidity bought nothing. Separately, Westenhoefer and Stewart found that rigid dietary restraint tracks with more frequent and more severe binge eating and higher disinhibition. Demanding a perfect month would buy no better result and would reward the eating style associated with the worse relationship with food. We are not going to build that.

Protein. Protein is judged on your 7-day average in grams per kilogram of bodyweight. Across meta-analyses of people who lift, muscle and strength gains slow sharply between about 1.3 and 1.6 g/kg a day. So full credit starts at your target or 1.6 g/kg, whichever is lower (1.8 g/kg in a calorie deficit, where needs rise), and never below 1.3 g/kg. Because protein is under-reported, a week within 15% of that level still earns full credit. Eating more protein is never marked down: studies in healthy adults show no harm to kidney function, and extra calories already count in the calorie half.

Logging, judged across the month. How much you logged is measured over the whole window, against five days in every seven since your first log, so a missed day costs a little on the day you missed it instead of knocking out a whole week. A week you only logged once counts as one day of evidence, not as a failed week, and Fuel as a whole is held near neutral until you have 14 days of food logged since the goal started.

We score calories and protein only, and they count equally toward each week. That split is our choice; no study sets it. Carbs and fat are what is left once those two are set, so scoring them separately would count the same thing twice and punish a trade-off that is entirely legitimate.

Is the work spread across what your plan needs?

Where we draw the line: 10–20 hard sets per muscle group per week.

Schoenfeld, Ogborn and Krieger pooled 34 treatment groups from 15 studies and found a graded relationship between weekly sets and muscle growth. Each additional set was worth roughly 0.37% more growth, with a threshold near 10 weekly sets per muscle group for close to maximal results.

Under 10 sets, a muscle group is below the range where it grows well. The upper bound of 20 to 25 sets, past which returns clearly diminish, is a practical convention rather than a meta-analytic number, and we treat it that way. Going over is flagged gently, not punished.

“Hard sets” means working sets you rate as two reps or fewer left in the tank. Easier sets do not count, or the window means nothing. That cut at two is our convention. An exercise that works several parts of one muscle group, like a row across your lats and upper back, counts once for that group.

A week here is never the calendar week, so Balance does not drop back to zero every Monday. We read the last fourteen days: the most recent seven count in full and the seven before them fade out day by day, which means a session leaves your record over a week rather than vanishing on day eight.

Each muscle group is graded against what your own plan asks of it that week, not a flat number, so following your split as written is never scored as a gap. Your first few sessions since a new goal are weak evidence of how your work is spread, a push day covers a third of the groups by design, so Balance is held near neutral until three sessions are in.

How long have you been consistent?

Where we draw the line: Six weeks to register, 66 days to matter, six months to max out.

Lally and colleagues followed 96 people forming new habits and found a median of 66 days to reach 95% of automaticity (the point where the behaviour stops taking conscious effort). The range was wide, 18 to 254 days, and complex behaviours like a full workout sat at the longer end, 60 to 150 days.

So our curve starts registering at six weeks, crosses its midpoint at 66 days, and saturates around six months. Past that, more time predicts nothing further.

The same study found that missing a single day barely matters. Automaticity dropped by less than half a point and recovered quickly. That finding shows up all over this score: one bad day is never treated as a setback.

This counts the days you actually logged a workout or a meal, across your whole time on Sculpt, not how long ago you signed up. It does not reset when you set a new goal, and a dormant account stops earning here. Like a thin credit file, it starts at zero, and at 5% of the score it can never outweigh real progress on your goal.