Martijn van Hooff became fascinated early in his career by the way the human body responds to exercise, and how small disruptions in blood flow can have major consequences for athletes. During his PhD research, Martijn developed innovative methods to measure oxygen saturation and pedal force patterns during exertion. These techniques allowed him to determine more quickly and accurately whether athletes were experiencing blood flow limitations in their vessels. His work not only improved diagnostic accuracy but also provided new insights into the effectiveness of surgical treatments.