Dr. Martijn van Hooff is a cardiopulmonary exercise physiologist, movement scientist, researcher, and co-developer of the FitMax questionnaire, a scientifically validated tool designed to estimate cardiorespiratory fitness (VO₂max) without the need for a maximal exercise test. His work focuses on exercise physiology, cardiopulmonary diagnostics, and translating scientific knowledge into practical applications for healthcare and clinical research.

Drawing from daily clinical practice, Dr. van Hooff recognized that conventional exercise testing is not always accessible or feasible for every individual. This observation became an important driving force behind the development of the FitMax questionnaire. By combining questions about everyday activities such as walking, stair climbing, and cycling, FitMax provides a simple yet reliable method for estimating exercise capacity and cardiorespiratory fitness.

In addition to his work on FitMax, Dr. van Hooff is involved in a variety of research projects related to exercise physiology, cardiovascular health, and rehabilitation. His ambition is to develop innovative, user-friendly assessment tools that help healthcare professionals and researchers better understand, monitor, and evaluate physical fitness.

With thousands of completed questionnaires and international validation studies, FitMax has evolved into a widely applicable instrument used around the world for research, screening, and health monitoring.