Case Study · Product Design
Designing a dual-platform mobile and wearable experience that helps personal trainers capture session data in real time, without losing the human connection that keeps clients coming back.
Chapter One
Personal trainers who manage four or more active clients constantly face the same impossible choice: look at their phone and log data accurately, or stay present and actually coach.
Most existing tools were built for planning and post-session review, not for the floor. So trainers delayed their notes, relied on memory after long days, and watched the accuracy of their data quietly erode.
Sometimes I have to ask a client to remember the weight they lifted while we were together to retroactively input data.
Personal trainer, interview participantThe Numbers
Chapter Two
We ran semi-structured interviews with personal trainers spanning 1 to 13 years of experience — different coaching styles, different client mixes, different definitions of "the floor."
The goal was to understand how documentation happens today, what breaks during live sessions, and how trainers decide what is worth tracking.
01
Empathize
02
Define
03
Ideate
What we found
Finding 01
Trainers prioritized eye contact and real-time cues, so they avoided any tool that required tapping, typing, or reading mid-set.
Finding 02
When logging happened later, details faded quickly across a day, which led to incomplete or incorrect records and weaker programming decisions.
Finding 03
Some wanted minimal tracking while others needed depth, reinforcing the need for progressive disclosure across the experience.
Survey insights
Insight 01
Trainees had higher consistency when effort felt seen and tracked — even lightweight progress views made a measurable difference in follow-through.
Insight 02
Data overload triggered confusion rather than clarity — a direct validation of our progressive disclosure approach. Show the minimum useful view first; let users pull for more.
Insight 03
Trainers bounced between calendars, notes, spreadsheets, and messaging apps every single day — a hidden cost that fragmented both their attention and their data.
Chapter Two · Continued
With research in hand, we moved into rapid ideation. Sketching let us explore structure. Wrong ideas were easy to throw out when they were still on paper.
We focused on two interaction models: a minimal wearable flow for the floor, and a deeper mobile hub for planning and review. Several sketch directions were explored before converging on the approach that best balanced speed with depth.
Wireframes
We translated the strongest sketch directions into low fidelity wireframes — a 26 screen mobile prototype and a 15 screen wearable prototype. The wireframes helped us validate structure first, without the distraction of color or typography.
From there, we ran moderated think-aloud tests with five participants using the low fidelity prototypes across both mobile and wearable. Their feedback shaped the navigation structure, the labeling, and the density of information shown at each step.
Usability testing
We conducted moderated think-aloud tests with five participants using low fidelity prototypes across both mobile and wearable. Participants completed tasks like accessing daily sessions, editing client information, customizing programs, and logging actions on the wearable during a simulated training moment. The biggest issues centered on navigation consistency, unclear affordances on cards, and confusion between similar actions. We addressed these through clearer labels, stronger visual cues, and more consistent paths.
Problem 01
Several participants hovered or hesitated on cards before tapping, unsure whether they were interactive or just informational.
Solution 01
Interactive cards now carry a clear visual signal: a chevron, a subtle shadow, and a pressed state that confirms the tap registered.
Problem 02
The "Add Workout" action was buried in an empty state with instructional copy rather than surfaced as a clear button, so the path forward wasn't obvious.
Solution 02
The action moved from buried instructional copy to a visible button alongside the Workouts label. A pre-populated workout item showed users exactly what adding one would produce — no guessing required.
Chapter Three
We designed Spotter as a mobile hub + low-attention wearable pairing. On the floor, trainers tap the watch to mark sets, adjust loads, and capture quick voice notes without breaking eye contact.
Off the floor, the mobile app organizes programs, sessions, and client history. A post-session summary reinforces trainee accountability and surfaces patterns over time.
Our color palette
Fun team color ideation!
The wearable
The wearable interface strips the experience down to its essentials. One tap to log, one tap to move on. Large tap targets, minimal text, voice fallback for everything that needs more detail.
01 — Launch
02 — Today's clients
03 — Pre-session
04 — Live logging
The mobile app
While the wearable handles the moment, the mobile app handles everything around it — client profiles, session programs, historical trends, and post-session summaries that write themselves.
My contribution
I took the Home and Session flows from initial wireframes through final implementation. I was also a key contributor to the final visual design system, helping design all mobile screens and wearable interfaces to create a cohesive cross-device experience.
Mobile prototype
Navigate the full mobile flow from home to session to post-session summary.
Wearable prototype
Click through the Apple Watch flow: log sets, move between clients, capture notes.
Reflection
Designing for trainers means designing for attention. The product succeeds only if it protects presence during the session — you can't just make something fast, you have to make something that doesn't ask for attention at the wrong moment.
Progressive disclosure works best when it starts from a clear definition of minimum useful data — not from a list of possible metrics. That framing changed how I think about every feature prioritization decision.
Navigation clarity depends on naming and structure. Small mismatches in labels can create big confusion when actions look similar.
What's next
Validate Spotter in real gym environments with working trainers and live clients.
Refine wearable interactions for faster use, like haptic patterns, clearer data entry labels.
Explore integrations with calendars, messaging platforms, and fitness data services.