PaceAI: Personalised AI Fitness Coach
Health & Fitness · React Native · iOS & Android · AI-Powered
PaceAI is a personalised fitness coaching app using AI to generate adaptive workout and nutrition plans based on goals, equipment, and real-time progress. Nine Pixels built the complete product (mobile apps, backend, AI integration, and wearable connectivity) from spec.
AI fitness apps fail because recommendations feel generic. The brief: coaching that adjusts based on how you actually performed, not just what you planned. Integrating real-time wearable data (Apple Watch, Garmin, Fitbit) with AI plan generation had to respond instantly, not stall.
Custom AI coaching layer on OpenAI's API using structured context injection, sending full fitness profile, recent performance, and biometric signals with an engineered system prompt constraining responses to evidence-based recommendations. A rules-based progression engine underneath prevents unsafe recommendations. UI uses a coach conversation metaphor rather than dashboards. Wearable data via HealthKit and Google Health Connect.
Our retention is 2x the industry benchmark. The context injection approach Nine Pixels built is what makes the AI feel like it actually knows you.