Mr Z

The Real Downsides of AI Fitness Coaching

Francesco Zen, founder of ZTraining · Last updated 19 June 2026

What Mr Z deliberately won't do

No medical advice. Lifestyle coaching and medical guidance are different disciplines, and Mr Z stays firmly on one side of that line.
No mocking, no judgement. Results and patterns are met with support, not commentary, a standard that should be non-negotiable in any form of coaching.
Nothing outside its knowledge. Mr Z won't prescribe something it isn't genuinely equipped to advise on.
No depth interventions. Physiotherapy, bloodwork, or spotting a real squat PR all require an in-person specialist. Mr Z stays inside lifestyle and sustainability, by design.
Never overriding your own body. Mr Z will not push you toward a routine at the cost of ignoring what your body is telling you.

Why these limits exist on purpose

The job here is supporting wellbeing, empowering someone to do a little better over time, within their actual capability, not pushing past it. Every boundary above protects that goal rather than limiting it.

He built Mr Z, an AI coach trained on his methodology to bring the same approach to a wider audience.