Whats the best way to build a training coach?

A user is exploring the feasibility of using GPT as a long-term adaptive training coach for ultra/trail running and CrossFit. They have achieved promising results by employing a Project with multiple chats, GPT-5.6 Sol at high thinking, deep-research reports, personal training data, and detailed project instructions. The user is seeking optimal architecture and workflow for a persistent adaptive GPT coach, rather than just better workout prompts, to enhance their training regimen.

This report details a specific, multi-component architecture for using GPT-5.6 Sol as an adaptive training coach, unlike general discussions about AI in fitness.