How to vibe codeFitbod

Prerequisites

• Node.jsfree

  Required runtime for Expo and TypeScript tooling.

• Expo Accountfree

  Required for building native iOS and Android client binaries.

• GitHubfree

  Version control and repository hosting.

AI coding tools

• Claude Code

  Handles multi-file TypeScript scaffolding, state management logic, and database schema generation directly from the terminal.

• Cursor

  Ideal for iterative UI tuning of workout logging screens and component styling.

Build guide

1. 01Initialize Expo TypeScript Project with Expo Router

   Scaffold a clean React Native mobile app structure using Expo with file-based routing and install required state management and local storage dependencies.

   Initialize a new Expo project using TypeScript with Expo Router file-based navigation. Set up a professional directory layout including /app (screens), /components (reusable UI elements), /constants (theme colors, exercise metadata), /db (SQLite management), and /store (Zustand state). Install lucide-react-native for icons and zustand for state management. Ensure strict TypeScript configurations are enabled and configure a clean dark mode color palette inspired by professional fitness apps with slate backgrounds and high-contrast accent colors.

   ⧉copy promptopen in Claude CodeCopen in Codexopen in Cursor

2. 02Build Local SQLite Schema for Exercises and Workout Logs

   Create a robust local database schema using Expo SQLite to store exercises, muscle groups, equipment profiles, workout sessions, and historical sets.

   Create a robust local database layer using expo-sqlite for an offline-first fitness tracker. Write migration scripts that initialize tables for: exercises (id, name, target_muscle, secondary_muscles, required_equipment, category), workouts (id, date, duration, notes), workout_exercises (id, workout_id, exercise_id, order_index), and exercise_sets (id, workout_exercise_id, set_number, weight_lbs, reps, completed). Seed the exercises table with at least 30 common strength training exercises covering chest, back, legs, shoulders, and arms with accurate muscle mapping and equipment requirements (barbell, dumbbell, bodyweight, machine).

   ⧉copy promptopen in Claude CodeCopen in Codexopen in Cursor

3. 03Develop Equipment Profile and Muscle Recovery State Engine

   Implement user settings for available equipment and a fatigue tracking calculation utility based on recent training history.

   Implement a TypeScript service layer that calculates muscle recovery percentages based on historical workout logs stored in SQLite. For each major muscle group (chest, lats, quads, hamstrings, shoulders, biceps, triceps, core), compute a fatigue score that decays linearly over 72 hours since the last logged session targeting that muscle. Create an equipment filter module allowing users to toggle available equipment (barbells, dumbbells, bodyweight, pull-up bar, resistance bands) which filters the active exercise pool accordingly.

   ⧉copy promptopen in Claude CodeCopen in Codexopen in Cursor

4. 04Implement Heuristic Workout Generation Algorithm

   Build the core recommendation engine that selects exercises and suggests weight/rep targets based on available equipment and muscle recovery status.

   Build a heuristic workout generation engine in TypeScript that selects 4 to 6 exercises for a requested workout split (e.g., Upper Body, Lower Body, Full Body). The algorithm must filter exercises by the user's available equipment profile and prioritize muscle groups with the lowest accumulated fatigue scores. For each selected exercise, query the user's historical performance logs in SQLite to automatically apply progressive overload by suggesting an incremental weight or rep increase over their last successful session for that movement.

   ⧉copy promptopen in Claude CodeCopen in Codexopen in Cursor

5. 05Create Interactive Workout Logging Interface

   Design and build the active workout session screen with set logging, weight/rep adjustments, live rest timers, and exercise swapping.

   Build an active workout tracking screen using React Native and Expo Router. The screen must display a list of generated exercises for the current session, each with a table of sets showing previous performance (weight and reps), editable inputs for the current set's actual weight and reps, and a checkbox/button to mark sets as complete. Include a persistent bottom bar with a live workout elapsed timer, a functional rest timer modal with preset countdown options (30s, 60s, 90s, 2m), and a button to swap any exercise with an alternative movement matching the same target muscle group.

   ⧉copy promptopen in Claude CodeCopen in Codexopen in Cursor

6. 06Add Progress Dashboard and History Log

   Build summary views showing completed workouts, volume progression charts, and muscle recovery heatmaps.

   Create a progress and history tab in the app. Build a workout history feed listing past completed sessions with expandable details showing total volume, duration, and exercise breakdown. Implement a visual muscle recovery screen or widget that displays a body map or list representing current fatigue levels across muscle groups based on recent training frequency. Ensure all queries perform efficiently against the local SQLite database.

   ⧉copy promptopen in Claude CodeCopen in Codexopen in Cursor

Cost vs paying for Fitbod