[Feature] Calculate 1RM from MCV data, track alongside PRs with gamification

[9thLevelSoftware]

Summary

Use Mean Concentric Velocity (MCV) data captured by VBT devices to estimate a 1-rep max (1RM) for each exercise, track that 1RM over time alongside the existing PR system, apply gamification when 1RM increases, and let users choose % of 1RM (not just % of PR) when programming workout set weights.

Motivation

Velocity-based training (VBT) devices already capture per-rep MCV, so a data-driven 1RM estimate is available without forcing the user to grind out a true 1RM. Combining (Weight, MCV) data from a variable set with a lift-specific Minimum Velocity Threshold (MVT) yields a personalized 1RM, and tracking it over time unlocks the same kind of progression and gamification we already apply to PRs.

Proposal

• For each exercise set, calculate a velocity-based 1RM estimate from the (Weight, MCV) data points of that set using a line-of-best-fit mapped to the exercise's Minimum Velocity Threshold (MVT).
• Persist / display this as a separate 1RM per exercise, alongside the existing PR value, in exercise history and progress views.
• Apply gamification (badges / streaks / progress notifications) when the velocity-estimated 1RM increases for an exercise.
• In workout set programming, add an option to set weight as % of 1RM in addition to the current % of PR option.
• Use MCV (Mean Concentric Velocity), not Peak Velocity (PV), for this calculation. PV is too erratic on standard strength lifts.

General MVT Defaults (1RM Velocity Thresholds)

Exercise	MVT (m/s)
Bench Press	0.15
Back Squat	0.30
Deadlift	0.15
Overhead Press	0.20

These are physiological averages; the user's actual MVT is stable per individual and can be inferred from a true RIR=0 rep (e.g. last rep of a heavy set of 3 or 5) — the MCV of that final completed rep is the user's personalized MVT for that lift.

Worked Example

Variable set yields:

• Rep 1 (Heavy): 225 lbs @ 0.38 m/s MCV
• Rep 3 (Dropped): 185 lbs @ 0.52 m/s MCV
• Rep 6 (Dropped): 155 lbs @ 0.68 m/s MCV

Plot (Weight, MCV), fit a line, and read off the weight at which the line crosses the exercise's MVT. That weight is the velocity-estimated 1RM for that exercise.

Steps to Reproduce / Validation Steps

1. Complete a variable set of an exercise (e.g. Bench Press) with a VBT device capturing MCV per rep.
2. Open the exercise history / progress view for that exercise.
3. Expected behavior: A velocity-based 1RM estimate is shown alongside the current PR, with a timestamp and the MVT used in the calculation.
4. Complete another variable set of the same exercise in a later session with higher velocity-estimated 1RM.
5. Expected behavior: 1RM updates, gamification (badge / progress notification) fires.
6. Start a new routine and edit a set's load.
7. Expected behavior: A % of 1RM option is available in addition to % of PR.

Expected Behavior

• A velocity-based 1RM per exercise is computed and stored, derived from per-rep MCV using a line-of-best-fit mapped to that exercise's MVT.
• 1RM is shown next to PR in relevant views (exercise history, progress / analytics).
• Increases in 1RM trigger the same gamification flow used for PR increases.
• A new % of 1RM option appears wherever % of PR is offered for set load programming.
• Personal MVTs override the general defaults once the user has at least one RIR=0 rep in their history for that exercise.
• All 1RM calculations use MCV, not Peak Velocity (PV).

Actual Behavior

Not specified — this is a feature request; current behavior does not provide velocity-based 1RM tracking, 1RM-side gamification, or a % of 1RM load option.

Implementation Notes / Open Questions

• Where to fit the line: per set, per session, or rolling window — needs a product decision.
• Whether to backfill 1RM history from existing logged sets that already have MCV data.
• Conflict resolution when velocity-estimated 1RM disagrees with a logged "true" 1RM (which one wins for PR vs. 1RM display).
• Personal MVT inference: minimum RIR=0 reps and minimum session count to trust a personal MVT over the general default.
• PV warning: ensure analytics / calculations do not silently switch to Peak Velocity for these strength lifts.

Missing Info / Follow-up Questions

• Should the velocity-estimated 1RM be allowed to be higher than a previously logged "true" 1RM, and if so, which value is treated as authoritative for PR comparisons?
• Do we need a user-facing toggle to switch between "% of PR" and "% of 1RM" globally, per routine, or per set?
• Should the gamification badge for "new velocity 1RM" be the same as, or distinct from, the existing PR badge?
• Any preference between storing a single 1RM value vs. a small time-series for the velocity-estimated 1RM (useful for trends)?

Screenshots / Attachments

None provided.

Original Discord Report

<@1502654170031849644> - Feature Request - Use MCV data to calculate 1 rep max for each exercise set and track 1RM for each exercise alongside current PRs.  Apply gamification for increased 1RM.  Option to use % of 1RM  instead of % of PR for workout sets.

To calculate your 1RM using your MCV data,  map your coordinates as (Weight, MCV). For example, if your variable set yielded these stats: 

Rep 1 (Heavy): 225 lbs @ 0.38 m/s MCV
Rep 3 (Dropped): 185 lbs @ 0.52 m/s MCV
Rep 6 (Dropped): 155 lbs @ 0.68 m/s MCV

You plot those points, draw your line of best fit, and see at what weight the line hits your exercise's Minimum Velocity Threshold (MVT)—which is the MCV of a true, max-effort failure rep.

General MCV Thresholds for a 1RM:
Bench Press:  0.15 m/s
Back Squat: 0.30 m/s
Deadlift: 0.15 m/s
Overhead Press:  0.20 m/s

Individualizing Your Thresholds
While these numbers represent standard physiological averages, your personal MVT is a stable individual trait dictated by your specific fiber-type composition and limb lengths.

If you want to find your exact threshold without actually performing a grinding 1RM, look at your VBT data for any set where you hit a Repetition in Reserve (RIR) of 0 (a true submaximal rep to failure, such as the last rep of a heavy set of 3 or 5). The MCV of that final completed rep is your personalized MVT for that lift. 

Quick Warning on PV (Peak Velocity).  If your VBT device tracks both, make sure your software isn't accidentally set to Peak Velocity for this calculation. PV is great for explosive, ballistic movements (like cleans, jumps, or speed-bench), but it is far too erratic for mapping a 1RM profile on standard strength lifts. Stick to MCV.

[9thLevelSoftware]

Additional info from Discord thread:

Follow responses:
True 1RM is the authoritative
% of 1RM can be a System wide setting along side the other velocity based options
Distinct badges for new velocity estimated 1RM
When estimating 1RM use the each set completed to plot and estimate 1RM
Yes, backfill 1RM history if existing logged data allows you to plot and estimate the 1RM

— added by ticket bot

[9thLevelSoftware]

Status update — velocity-based 1RM is in active development 🛠️

Thanks for the detailed write-up. The MCV → 1RM approach maps cleanly onto the VBT engine the app already has, so much of this is wiring existing pieces together rather than building from scratch. A design spec and a phased implementation plan are now committed, and the foundation is being built on the feat/issue-517-velocity-1rm branch.

Design decisions locked in:

• Estimation — reuses the existing load↔velocity OLS regression (the same math behind the in-app VBT assessment), now run automatically over a rolling window of your recent sets per exercise (needs ≥2 distinct loads to fit a line). MCV only, never Peak Velocity — per your warning.
• MVT — per-movement-pattern defaults (bench 0.15, overhead press 0.20, squat 0.30, deadlift/hinge 0.15, with a 0.20 fallback), plus a personalized MVT that overrides the default once enough near-failure (RIR≈0) reps are seen for that lift.
• % of 1RM — added as a first-class scaling basis alongside % of PR, with a system-wide default setting (as confirmed in the thread).
• Gamification — a distinct badge for velocity-1RM progress, separate from PR badges.
• Authority — a logged "true" 1RM stays authoritative; the velocity estimate is tracked as its own time-series next to your PRs.
• Quality gate — every estimate is stored, but only those with a clean regression fit are shown / trigger badges, so noisy days don't pollute your numbers.
• Backfill of historical sets and portal display are sequenced as later phases.

Done so far (tested): the estimator core, the movement-pattern + MVT model, and the persistence/repository layer for the 1RM time-series.

Next up: automatic computation on workout completion, the % of 1RM scaling option + badges, backfill of existing data, and surfacing the value in the app and portal.

Will keep this thread updated as the remaining phases land.