RPE (Rate of Perceived Exertion)
half-step scaleThe cleanest available proxy for effort. Half-steps are granular enough to be informative and coarse enough not to fake precision.
← For muscle nerds
Nine signals tracked.
Nine signals tracked.
Six refused, on purpose.
Each tracked metric is computable from the data you've already logged — no external sensor, no subscription, no marketing partnership we can't tell you about. The refused list is shorter than the tracked list, and that's intentional.
Nine signals. All disclosed.
Each one carries a literature reference (or a clearly-named in-house heuristic) in its footer.
RIR (Reps in Reserve)
derived from RPEThe arithmetic dual of RPE. We track both so the user can think in whichever framing they prefer.
Estimated 1RM
computed per setA back-calculated single-rep max. Lets you compare 225×5 to 245×3 honestly. We use a formula with strong literature support across the working-rep range.
Fractional set volume
multi-axis muscle volumeA bench press contributes to chest, triceps, and front delts — but not in equal measure. We weight primary movers more than secondary movers. Counting everything as a full set implies your triceps grew at the rate of your chest; we trust your triceps to disagree.
Effective reps
reps performed close to failureHypertrophy lives near failure. A set of 20 at RPE 6 is mostly cardio. We don't care about cardio sets when we're asking "did this grow tissue?"
Movement patterns
a small fixed taxonomyPush, pull, squat, hinge, carry, lunge, core, rotation. Coarse, durable, and meaningful — patterns survive any individual exercise being renamed or retired.
Tempo (optional)
per-phase secondsCaptured per set for users who care about tempo work. Most lifters never touch it; the ones who do want it logged precisely.
Rest interval
per set, secondsCaptured from the rest timer; editable. Drives the workout rhythm waveform and post-hoc fatigue analyses.
Body weight + bodyfat %
HealthKit-syncedTwo-way sync with Apple Health. Body weight matters for relative-strength comparisons. Bodyfat % matters for body-composition trends (and almost nothing else).
Honesty is also a feature.
The shortest list in the app world. Most workout trackers add metrics that look impressive in screenshots; we'd rather ship six that mean something than sixteen that don't.
Velocity-based training (VBT)
NOT TRACKEDWe have no business between your bar and your barbell collar. Velocity tracking belongs to the hardware that can actually measure it.
Open Settings → Export and pipe the CSV into your own VBT spreadsheet if you must. We won't fight you.
Percentage of 1RM
NOT TRACKEDYou can compute it yourself from e1RM at any time. Storing it separately means it goes stale the moment you PR — and stale data is worse than no data.
If your program is written in %1RM, the methodology card on every e1RM chart will help you translate.
HRV-based "recovery scores"
NOT TRACKEDHeart-rate variability is mostly noise plus your phone's barometer plus how much coffee you had. We could pretend it was a signal. We don't.
If you have a Whoop, follow Whoop. If you have a Garmin, follow Garmin. We're not a wellness company.
Perceived recovery scales (1–10)
NOT TRACKEDA user-reported number with no calibration and no anchor. We'd ship a feature that looks impressive in screenshots and conveys precisely nothing.
You can write "felt slow" in the notes field. That's more honest.
Streak length (gamified)
NOT TRACKEDWe track consecutive training days as a stat. We refuse to gamify it. No "DON'T BREAK THE CHAIN" notifications. No streak-shame.
Milestone streaks get a small, quiet acknowledgment somewhere in the app. We won't tell you where; you'll see it when it happens.
Social leaderboards
NOT TRACKEDflexRep is not a social network. Our brand stance on this is firm and not up for debate.
Share-cards exist. A feed does not. We don't plan on shipping one.