Methodology
Can You Build Muscle and Lose Fat at the Same Time?
Francesco Zen, founder of ZTraining · Last updated June 19, 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 starting at or below roughly 20% body fat. 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.
- Improved cardiovascular activity, alongside the muscle gain itself.
Related: Body-fat threshold rules for building muscle · How to break a fat loss plateau
Francesco Zen is the founder of ZTraining and ZLIFE, with 18 years of coaching experience working with executives across the UK, US, and UAE. He built Mr Z, an AI coach trained on his methodology to bring the same approach to a wider audience.