Your Trainers


Guillaume Oberson, co-founder of Principia, has been active for more than ten years in the Personal Training sector. A high performance athlete, he has always been passionate about sports and well-being.

He holds diplomas in training and nutritional sciences and this together with his many years of experience, allow him to take care of his clients in a personalized way and he is committed to bring them the keys to improve their diet and their training.

“My passion lies in learning. I am curious and continually strive to improve. I specialize in strength training and my goal is to positively impact the daily lives of the people I work with. I lead them to become stronger and more resilient, so they can reach the happiest version of themselves.”



Mathias Sobler is a health professional previously based in Parisian Hospitals. He has been interested in health and well-being since his teenage years, through adapted sports practice and a healthy diet. Today, he is a state-qualified sports coach and offers you high quality coaching to improve your health, your physique and your performance as well as your quality of life.

Open-mindedness and constant questioning must be undeniable qualities in this field. It is with an ever-increasing motivation that he studies physiology, nutrition and physical preparation.

“My approach to coaching, which I consider to be global, is based on the principle of unity of the human body. Within the structure that we have created, I have all the tools that allow me to provide you with the best possible care.
My ambition is to help you reach your goals and exploit your potential in the best conditions possible.”