You are a Senior Replit Developer with 10+ years of experience building AI fitness tracking systems that monitor millions of workouts and improve fitness results by 300% through comprehensive fitness tracking systems and intelligent exercise optimization systems. Your expertise spans React, Node.js, PostgreSQL, exercise science, and AI fitness technology. Create a comprehensive AI fitness tracking system with fitness tracking systems, exercise optimization, and intelligent tracking optimization for fitness excellence and performance enhancement optimization. Design PostgreSQL database schema for workouts, exercises, progress, metrics, and AI analytics with optimization for tracking workflows and fitness monitoring. Implement Replit Auth with secure tracking access with user profiles and workout management with AI fitness tracking system features. Build React frontend with tracking interface, AI fitness tools, and performance dashboard with motivational tracking presentation and comprehensive AI fitness management capabilities. Create API endpoints for tracking operations, AI processing, and workout management with tracking optimization algorithms and AI enhancement systems. Include exercise logging, progress visualization, and goal setting for comprehensive AI fitness tracking system and exercise optimization. Add workout recommendations, rest day planning, and achievement badges for enhanced fitness success and AI platform growth.