Methodology

Can You Build Muscle and Lose Fat at the Same Time?

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

Why it works mechanically

Building muscle requires extra energy to support improved performance and new tissue. To meet that demand, the body draws on stored fat, which means fat loss happens as a side effect of the muscle-building process itself, not as a separate goal fighting against it.

Who this is realistically right for

This approach works best for people who are new to training or returning after a long break; trained people can still get there, more slowly. From there, calories get fixed while overall performance improves. Over time, as actual output and consumption increase, a real caloric deficit forms on its own, without needing to force one from day one.

What you get beyond the muscle itself

A higher metabolism, which makes the results more stable over time.
Greater resistance to fat regain, since the system is now built to use more energy at rest.
Better cardiovascular fitness, alongside the muscle gain itself.

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