Architecture

The app's progression boils down to 3 simple lists with rules connecting them. Think of it like 3 tabs in a spreadsheet.

Tab 1: Exercise Database

One row per exercise. Hundreds of entries eventually. Each exercise knows what it builds on and what it pairs well with — that's how the app creates individualized progressions.

Key concept: Users start with single exercises. As they master them, the app introduces paired exercises (synergistic combos) for more benefit in the same time.

Hip Flexor Stretch 90s • Difficulty 1
Body area: Hips • Setting: Floor
Concerns addressed: Hip tightness, back pain, sitting recovery, pelvic floor
Builds on: None (starter exercise)
Pairs with: Glute Bridge (antagonist — open then activate)
Progression steps: 20s hold → 30s hold → add arm reach → elevated back foot
Single-Leg Stand 60s • Difficulty 2
Body area: Balance/Core • Setting: Standing
Concerns addressed: Balance, fall prevention, independence, core strength
Builds on: Weight Shifts (must be "learned" first)
Pairs with: Calf Raises, Glute Bridge (stability + strength combo)
Progression steps: 10s eyes open → 20s → 30s → eyes closed 10s → eyes closed 20s
Towel Squeeze 45s • Difficulty 1
Body area: Grip/Hands • Setting: Seated
Concerns addressed: Wrist & hand mobility, independence, grip strength
Builds on: None (starter exercise)
Pairs with: Finger Spread (open + close grip pairing)
Progression steps: Light 5s → Firm 5s → Max 5s → Squeeze and hold 10s
Target: several hundred exercises. 26 drafted so far. Columns per exercise:
Name, Body Area, Difficulty (1-3), Time, Setting (Standing / Seated / Desk / Doorway / Floor / Wall / Equipment), Concerns Addressed, Builds On, Pairs With (+ why), Progression Steps.
Setting drives nudge filtering — office break? Standing/Seated only. Home evening? Floor is fine.
Aunt's PT expertise needed to fill this out properly.

Tab 2: Progression Rules

The if/then rules that drive the whole app. Confirmed with Faith, Mar 22.

Nudge Delivery

Window: 8am – 6pm only (desk hours)

Frequency: 2–4 nudges per day, user selects during onboarding

Spacing: At least 2 hours between nudges

Timing: Placed in calendar gaps (15+ min free)

Each nudge contains: 1 exercise + 1 insight + feedback prompt

Exercise Selection

Concern filter: Only exercises matching user's onboarding concerns

Daily variety: Different exercise each day — no repeats day-to-day, even if not yet "learned"

Within a day: Same exercise for all nudges that day (reinforcement)

Setting aware: Picks exercises matching practical setting (Standing/Seated for office hours)

Swap button: User can tap "Swap today's focus" to get a different exercise (user-initiated, not automatic)

Progression & Feedback

After every nudge: "How did you find this?" → Easy / Challenging but doable / Couldn't complete

Level up: Two "Easy" responses in a row → advance to next progression step (or next exercise if at highest step)

Stay course: "Challenging but doable" → keep current progression step

Dial back: "Couldn't complete" → offer easier variation or step back one progression level

Exercise learned: "Easy" twice at the highest progression step → exercise mastered, rotate out

Unlocks & Pairings

Prerequisites: Don't assign an exercise until its "Builds On" exercise is learned

Paired exercises: After a user has learned several single exercises, introduce synergistic pairs (e.g., Hip Flexor Stretch + Glute Bridge together)

Insights: One per nudge, matched to the exercise and user's concerns. Short (2–3 sentences). Evidence-based with citations.

Sources: Q17 (feedback), Q18 (progression), Faith session Mar 22. No fixed timeline — user's pace drives everything.

Tab 3: Sample User Journey

Sarah, 42, desk job. Picked "back pain" and "better posture" at onboarding. Chose 3 nudges/day.

Day 1 Chest Opener (Standing, 60s)

9:15am — Nudge 1 during meeting gap. "Stand up, clasp hands behind your back, squeeze shoulder blades. 20s, 3 times."

Insight: "Sitting rounds your shoulders ~2mm per hour. What you just did reverses that."

Feedback: Challenging but doable

12:30pm — Nudge 2 at lunch. Same exercise, different insight.

3:45pm — Nudge 3. Same exercise. Feedback: Challenging but doable

Day 2 Seated Spinal Twist (Seated, 60s)

Different exercise — still targets back pain. All 3 nudges today are Seated Spinal Twist.

Insight: "Your thoracic spine was designed to rotate 35°. Most desk workers manage about 15°."

Feedback: Easy, Challenging but doable, Easy

Day 3 Shoulder Shrugs (Desk, 45s)

New exercise. Desk-friendly — she can do it without leaving her chair.

All 3 nudges: Easy. Two "Easy" in a row → progression advances to next step.

Day 7 Cat-Cow (Floor, 60s) → SWAPPED

App picks Cat-Cow (great for back pain). But Sarah's at the office — no floor space.

She taps "Swap today's focus" → app picks Wall Angels (Standing) instead.

Setting filter kicks in on swap, picks from same concern pool.

Day 14 Milestone!

Sarah has done 5+ different exercises. Milestone unlocked.

Shoulder Shrugs fully learned (Easy at highest progression step).

Thoracic Rotation unlocks (its prerequisite Cat-Cow was learned on Day 10).

Week 8+ Paired exercises introduced

Sarah has learned several single exercises. App introduces her first pair:

Hip Flexor Stretch + Glute Bridge (antagonist pairing — open then activate)

Same nudge, two exercises, still under 3 minutes total.

This is one user's journey. Different concern picks → different exercises → different pace. The rules in Tab 2 generate infinite personalized journeys from the exercises in Tab 1.

Status: Tab 1 drafted (250 exercises), Tab 2 confirmed, Tab 3 sample done

Next: Aunt reviews exercise database. Then we build.