LunaFit — Adaptive AI Coach

LunaFit — Adaptive AI Coach

OUTCOME

Turned a menu-heavy fitness app into a voice-first AI coach that adapts in real time — cutting cognitive load and turning one-off sessions into daily habits.

FEATURES

Voice-first AI coaching, Adaptive logging, Habit-forming progression loops, State-driven micro-interactions

Problem

Traditional fitness apps rely on static menus and manual logging, creating friction during workouts and making it difficult for users to know what to do next. This led to low activation, inconsistent usage, and a lack of personalized guidance or emotional support.

Solution

I designed a conversational AI Coach that replaces rigid navigation with real-time, context-aware guidance. Instead of navigating menus, users interact with the coach to log actions, ask questions, and receive adaptive support, reducing cognitive load and creating a more intuitive, guided experience.

Product

The LunaFit AI Coach is a persistent, in-app assistant that functions as the primary interface layer, guiding users across onboarding, workouts, and progress tracking through conversational and voice-driven interactions.

Key Features

Experience redesigned to drive behaviour

From form fatigue to guided momentum

Replaced a long, static onboarding flow with a conversational, coach-led experience that adapts in real time.

The coach-led onboarding dialogue
  • Reduced a 17-step form into dynamic, step-by-step guidance
  • Asked only what's needed, when it's needed
  • Shifted onboarding from setup to first moment of value
  • Users begin interacting immediately instead of filling forms

Designed for in-the-moment use

Optimised core workout flows for real usage during a workout, not just static UI clarity.

Weight logging and the workout player
  • Prioritised the current lift over history in weight logging
  • Reduced taps and cognitive load during sets
  • Surfaced progress in real time
  • Validated through usability testing with strong user preference

From feature to constant presence

Transformed the coach into a persistent, state-driven system rather than a secondary feature.

The always-present coach in contextVoice and text unified into one input model
  • An always-visible coach replaces deep navigation
  • Voice and text inputs unified into one interaction model
  • State-driven responses (idle, talking, listening)
  • The system feels responsive and alive instead of scripted

Making progress feel visible

Addressed early drop-off by designing for motivation and progression.

  • Introduced streaks, levels and phases
  • Reframed workouts from repetition to progression
  • Reinforced consistency through small wins
  • Designed specifically to improve early retention

Experience to behaviour change

Together these shifted the product from a tool into a system users consistently return to.

  • Increased onboarding clarity and completion
  • Reduced friction during workouts
  • Stronger feedback loops for motivation
  • Improved retention signals and engagement