Mr Z
Which AI Model Is Mr Z Built On?
Francesco Zen, founder of ZTraining · Last updated 19 June 2026
What "built on a large language model" actually means here
A large language model powers the conversation itself. The model provides the engine. The method provides everything that actually matters in the advice itself.
Why this distinction matters
Plenty of AI tools are a generic model with a fitness-themed prompt attached. Mr Z is the reverse: a specific, tested coaching method, encoded into an AI built to deliver it consistently, at scale, to far more people than one coach could ever reach alone.
Related: Why I built an AI version of my coaching method · An AI coach in your browser, why and how
He built Mr Z, an AI coach trained on his methodology to bring the same approach to a wider audience.