Equations
The formulas the app runs.
Weights are stored in pounds. Settings: Progression settings.
Estimating your max
Estimated 1RM
weight × (1 + (reps + RIR) ÷ 30)
The Epley equation with effort folded in. RIR = 10 − RPE.
No RPE means RIR 0. Reps + RIR is capped at 15. Example: 100 lb × 8 at RPE 8 = 133.3 lb.
Training max basis
entered training max wins; else best same-range e1RM, capped at a lowered working 1RM
Progression
A program day progresses from its own history. The same lift on another day shares it only when the prescription matches.
RPE-based progression
reps + max(2, round(10 − RPE)) · at the top: load + increment × m
m = 1 + (trigger − RPE) ÷ 2, capped at 2.
- Gate: progress when the top-set RPE is at or under the Top-set RPE trigger (7, 8, 9 or Off; default 8). Otherwise the target holds.
- Reps first: RPE 8 adds 2 reps, RPE 7 adds 3, RPE 6 adds 4.
- Then weight: past the top of the range, load goes up and reps reset. With trigger 8, RPE 7 earns 1.5× the increment, RPE 6 or lower 2×.
- Timed work: an earned step adds 2 time steps (+10 s by default).
Linear progression
load + increment, every session
No RPE gate. Reps carry over, pulled into the range. A work set below the range repeats the load; a top set below it goes through Back into range.
Back into range
reps + whole RIR ≥ range min ? keep load : e1RM ÷ (1 + (mid reps + RIR) ÷ 30)
Linear mode, top set below the range. If reps + RIR reaches the minimum, the load stays; if not, it drops to fit mid-range reps. Example: 245 lb × 2 at RPE 7, range 6–12 becomes 205 × 9. Weighted bodyweight and assisted lifts hold the load and step reps.
Load increments
Weight: w + v · Percent: w × (1 + v ÷ 100), to the nearest 5 lb (2.5 kg)
Default increment: 5 lb.
- Formula loads (%1RM, deloads, rebases) round to a multiple of your increment.
- Dumbbells step to real weights (20 or 25 lb a hand, never 22.5). In kg: 2.5 kg steps from 10 kg, 1 kg below.
Program loads
%1RM target
basis × pct ÷ 100, rounded to increment
Basis: your training max basis.
pct is the first of: the set's own %, the exercise's %, the week's stage %, the program's % of 1RM, then 75%. Range 1 to 100. Reps carry over from your latest top set.
Working 1RM
offer = max(best of last 3, 90% × working, 80% × all-time best)
Only when each of the last 3 hard sessions is 7% or more under the working 1RM, within 6 weeks. Applies when you tap Use.
- Hard session: a work set at RPE 7+ and 10 reps or fewer. Off day workouts and deloads don't count.
- Layoff: 4+ weeks off offers 5% lower, 8+ weeks 10%, never under 80% of your best.
- At most one lowering per 6 weeks. Your best and PRs never go down. Screens: Working 1RM.
Deload week
normal load × deload %, rounded to increment
Default 60%, between 40% and 80%.
- Runs on a Deload stage week or after Deload this week.
- Bodyweight reps scale, never below the range.
- Stall deload: 3 stalled sessions at one weight bring a 90% suggestion, applied only if you tap it.
Logging and stats
Warm-up ladder snapping
working weight × rung %, to the nearest 5 lb (2.5 kg)
Working weight: your heaviest entered work set, or the suggested target. Default rungs: 40% × 5, 60% × 3, and with 3 rungs 80% × 2. See Warm-ups and supersets.
Dumbbell weight
stored total = 2 × weight per side
Pair weight entry (Settings → Display & Units) is Per side (default) or Total. One-dumbbell lifts store the weight as entered. Volume and PRs use the total.
Volume
weight × reps, per work set, added up
Warm-ups and distance work count 0. Muscle views give primary muscles 100% and secondary 45%; set counts give both a full set.
Sources
- Zourdos MC, Klemp A, Dolan C, et al. (2016). Novel resistance training–specific rating of perceived exertion scale measuring repetitions in reserve. Journal of Strength and Conditioning Research, 30(1), 267–275. doi:10.1519/JSC.0000000000001049
- Grgic J, Lazinica B, Schoenfeld BJ, Pedisic Z (2020). Test–retest reliability of the one-repetition maximum (1RM) strength assessment: a systematic review. Sports Medicine – Open, 6(1), 31. doi:10.1186/s40798-020-00260-z