AI-Powered Fitness Tracker

A React-based fitness application that uses OpenAI's API to generate personalised workout and meal suggestions for beginners.

Features

• AI workout generator — tells you exactly what to do based on your fitness level, available equipment, and goals

• Meal suggestions — generates meal plans that align with your calorie and macro targets

• Progression tracking — logs your workout history and visualises progress over time

• Adaptive difficulty — suggestions get harder as you improve

Tech Stack

• React for the UI

• Node.js + Express for the backend API proxy

• OpenAI API for workout/meal generation

• LocalStorage for persistent history (no auth required)

Architecture Note

All AI calls go through a Node.js proxy to protect the API key. The frontend never touches the raw OpenAI endpoint.

What I Learned

Prompt engineering is a real skill. The difference between a generic "suggest a workout" prompt and a structured prompt with user context, equipment constraints, and output format specifications is dramatic. Getting consistent, parseable JSON back from the model required significant iteration.

Source: GitHub