A mobile MVP that brings the quality of a NABBA-certified personal trainer into an AI-driven app. From paper wireframes, through 6 qualitative interviews, to a fully documented product with 17 hi-fi screens and its own visual system — all in a 4-week sprint.
Delivered: 17 hi-fi screens, 3 subscription tiers, a complete design system, and 100% task completion in usability testing.
17 screens · 60fps transitions · Smart Animate + CSS
Precision training has always been reserved for those who can afford it. A certified NABBA personal trainer costs $200–500 USD per month — out of reach for 80% of the users I interviewed. Meanwhile, generic fitness apps ignore somatotype, body composition, and individual context, treating every user the same.



How might we give anyone with a fitness goal access to the same quality of analysis and planning that an elite athlete gets from a personal trainer — using AI + human validation?
Each pain point is paired with the participant count and a direct quote from the research corpus.
"Excel + photos + apps = chaos"
"I'm never sure if I'm doing the exercise right"
"There's no evidence of the process"
"I got tired of logging everything"
"Every participant uses an external coach or nutritionist"
The pattern was clear: tools are fragmented, validation is missing, and the human layer is non-negotiable. No single app on the market was closing this loop.
Six in-depth qualitative interviews — recorded, transcribed, and synthesized through affinity mapping. Participants ranged from NABBA-certified trainers to recreational athletes and intermediate fitness users.
Every raw insight from the 6 interviews was written on a card, clustered into themes, and validated. This became the backbone of the product's feature prioritization.
Four data points that shaped every subsequent design decision:
Every single participant — 6 of 6 — explicitly preferred human validation over AI-only recommendations.
5 of 6 users manage their training, nutrition, and tracking across 3+ separate apps or files.
4 of 6 users lack a clear way to see their physical evolution — no consistent photo timeline.
2 of 6 quit tracking nutrition entirely due to logging fatigue — a clear adherence signal.
Direct quotes from participants, grouped by the 4 emergent themes:
From the 6 interviews, three archetypes emerged. Each persona includes real quotes, real tools they use today, and the gap FitLab needed to close for them.
"If there was software that helped me keep everything in one place — it would make me better, faster, easier."
"I come up short with Excel when transmitting technique correctly… the variables in the routine just don't fit."
"I'd rather a person evaluate me… maybe my body just can't achieve certain goals an AI proposes."
Before opening Figma, I mapped the entire experience on paper. Hand-drawn wireframes let me think about hierarchy, flow, and decision points without getting distracted by visual polish — a method I pulled directly from NNGroup's Design Thinking discipline.
The full product flow sketched by hand: onboarding, objective selection, level, photo capture, motivation, accompaniment preference, and more than 15 decision points. Every screen in the final product traces back to a frame in this flux.


User-centered · Corpus UX research-based · Benchmarking-validated
Before jumping to hi-fi, I iterated on three mid-fi wireframes to validate the structure of the most critical screens: daily nutrition, workout detail, and weekly overview. Mid-fi lets you test hierarchy and information density without committing to the visual system yet.
Active phase, daily macros, pre/post workout distribution. Key decision: surface calories before macros to reduce cognitive load during the training window.
List of 8 exercises with gold muscle tags, primary CTA to start workout, secondary to preview video. Test hypothesis: less than 2 taps to begin a set.
Progress visible at first tap. Micro-copy "HOY" anchors temporal context. Completed states with cyan check for positive reinforcement without celebration overload.
My first hypothesis was an AI-only product — faster to build, lower cost, scalable. Then the research said something the product direction couldn't ignore:
100% of participants prefer expert human validation over pure AI recommendations.
This single finding reshaped the entire product architecture. The Pro tier — with a certified NABBA coach reviewing every AI analysis — wasn't a "premium feature" anymore; it was the trust layer the whole product depended on.
Beyond the metrics cards above, I built a clickable Figma prototype of the full flow and walked a handful of users through it — qualitative feedback only, not instrumented metrics. The main takeaways informed the focus-mode iteration and the 2-tap logging decision documented in the Learnings section.
The product breaks into three functional layers — each one designed to close a specific research gap. Together they form the "AI + Expert" loop that differentiates FitLab from every competitor I benchmarked.
Closes the gap: "generic apps ignore my body composition"
User uploads 4 NABBA-standard photos (frontal relaxed, frontal flexed, lateral, back). The AI returns somatotype classification, symmetry analysis, and prioritized muscle groups — in under 2 minutes. On Pro, a certified coach reviews the output before it reaches the user.



Closes the gap: "registration kills the hab — if it's more than 2 taps, I quit"
The fastest set-logging flow I could design. A dark focus mode hides every distraction except the current set — technique animation, rep target, rest timer. Tap once to log, tap once to start the next set. Two taps, zero friction.



Closes the gap: "80% of users abandon in 2 months because they don't see changes"
Progress isn't one metric — it's three. Strength data (PRs, volume, adherence), visual evidence (photo timeline with AI-detected changes), and body measurements (weight curve, circumference by segment). Each view feeds a different motivational trigger.



17 hi-fi screens — every one traced back to a frame in the Raw UX Flux, refined with insights from the research corpus, and built with a single component library under a documented token system.
This is what the user sees the moment they open FitLab. A liquid-glow onboarding entry — logo reveal, staggered brand gradient, ambient particles — designed to set a "scientific but warm" tone before the onboarding flow even begins. Built entirely in HTML + CSS (no video, no GIF) so it stays crisp on any device.
Runs once on every cold start. The logo enters staggered — "Fit" in white first, "Lab" in the brand gold gradient with a 300ms delay — then a gold line expands underneath and the tagline fades up. Total duration: 2.4 seconds. Designed to feel fast but intentional.
Organized by flow: onboarding, dashboard + AI analysis, plan, workout session, progress tracking, profile.
















Every scientific decision in the product — from the 4-pose photo protocol to the somatotype classification (Ectomorph / Mesomorph / Endomorph) — follows the National Amateur Body-Builders Association standard for natural physique development. This isn't a marketing label; it's the basis for why trainers in the research corpus trusted the output.
Six features that — together — no competitor in the fitness market offers today. I benchmarked MyFitnessPal, Strong, Dr. Muscle, Caliber, and Hevy; each solved one or two of these. None solved all six.
On the Pro tier, a NABBA-certified coach reviews the AI output before the plan activates and schedules a 1-on-1 video session every 4 weeks. This is what turns FitLab from "another AI app" into a hybrid product with a defensible moat.
First app to implement NABBA methodology digitally. 4 photos → somatotype + priority muscle groups in under 2 minutes.
On Pro, a NABBA-certified coach reviews the AI output before the plan activates. The trust layer that makes the whole product credible.
The algorithm compares photos from different weeks and detects muscular changes the eye can't: relative volume, symmetry, segmental proportion.
The plan adjusts volume, intensity, and exercises based on actual adherence, recorded PRs, and progress metrics. Never a static plan.
Macros calculated and adjusted per training phase (bulk, cut, maintenance). Synchronized with the workout calendar automatically.
Pro users export full training, nutrition, and body-metric histories. Designed for coaches and advanced athletes who need external analysis.
Users wanted to know why the AI was recommending specific exercises. In v2, contextual micro-explanations go in every recommendation.
The photo-analysis flow felt intimidating for beginners. High-value steps need more context and gradual progression — not fewer screens.
Designing 3 product tiers in parallel was the hardest part of the sprint. Business model can't be a last-minute decision — it shapes every flow.
Every second the user thinks about the app mid-workout is a second they're not training. The best fitness UX is the one you don't notice.
All research photos, participant profiles, prototype flows, and design-system artifacts — in a Figma presentation format. Hosted on Figma Deck.
Two more case studies — a published B2B SaaS redesign and self-initiated research on Spotify.