I'm experimenting with using GPT-4o (via OpenAI’s o3-pro) as a swim coach—part analyst, part training partner. This post is the second in a series documenting how it’s going, including how I’ve adapted the workflow to be more human-led and how I'm building a SwiftUI app that connects directly to Apple Health for automated, AI-powered feedback. If you're curious about applied AI, quantified self, or just hacking better habits, I’d love your thoughts.