This is how you build muscle mass forever, experience permanent physical and mental fitness

I am leading you, as a male athlete, to a transformation with more muscle mass without a strict diet or long workouts.

Start building muscle today on the long term. Not a quick fix, but zichtbaar resultaat for always with mijn Flexibele Methode. 

Progression of muscle mass Jordi de Haan

I am Jordi de Haan, currently personal trainer & online coach and has been involved in fitness since 2010. I also have training personal trainer and nutritionist rounded.

apart from that I am specialist in the field of building muscle with a flexible diet for men. This flexible method allows you to: consistent building muscle mass for the rest of your life.

Through my flexible method I already have 200+ male athletes helped with muscle mass without that they are strict about it nutritional guidelines handled.

Progression of muscle mass Jordi de Haan
helped people
created training programs
hours of personal training provided

My Flexible Method

"Flexible = means, consistency = goal."


We go for it together continuous changes in the field of mental and physical fitness.

Flexible method for muscle mass


Gain knowledge through Understandable language, making it applicable in practice. Prevent injuries!

Flexible nutritional plan

Take your calorie needs into account and learn to eat accordingly feeling immediately flexible diet.

Efficient workout

Train efficiënter, niet langer! Met gerichte trainingen, afgestemd op jouw lichaam, behaal je resultaten in minder tijd.


To persevere during slower periods, due to intrinsic motivation for the gym.

Progress registration

Easy tracking of your progress and every week better want to be in a training.


Developing a lifestyle in which weight training & health be present in the long term.


Ronald Beuker progression
Progression of muscle mass
Progress Luuk

This is how you book
3 steps
long-lasting results

It's all about achieving long-lasting results so that you in the long run make physical and mental progress. It is a significant investment in yourself, but it will help you achieve results inside and outside the gym. Thanks to more muscle mass: 

build flexible muscle mass

'Build Flexible Muscle Mass' via online coaching

Watch the video of the training app.

Create Super fast muscle mass via 'Building Flexible Muscle Mass'. Take advantage of the 11 years knowledge and experience!

smu play button

Watch the video of the training app.

Guidance in the gym through Personal Training

Do you want you technology improve your training program? Then you can also take personal training sessions in the city of Utrecht.

Entirely based on you training goals and needs.

Personal training Utrecht
the flexible method mockup 2

Train you with too little results?

Essential principles for lasting and consistent building of muscle mass.


Free Ebook:

Everything about muscle mass

Avoid stopping fitness due to lack of results. Continue building muscle mass forever with this e-book!

Continue building muscle mass forever with this e-book.

Everything about Muscle Mass ebook