Jo Nijs, PT, MT, PhD, is a Belgian professor of physiotherapy at the Vrije Universiteit Brussel and physiotherapist/manual therapist at the University Hospital Brussels. He is Scientific Chair of the executive committee of the Pain, Mind and Movement Special Interest Group of the International Association for the Study of Pain (IASP) and holder of the Chair 'Exercise immunology and chronic fatigue in health and disease' funded by the European College for Decongestive Lymphatic Therapy. Nijs plays a leading role in the Pain in Motion research group, an international collaborative that studies the interplay between chronic pain and movement. While he advocates graded exercise as a treatment for ME/CFS, he argues that it should be preceded by a stabilization phase in which patients pace themselves to find the right balance between rest and activity. Nijs is mostly known for espousing the theory of central sensitization: he suspects ME/CFS to be a dysfunction of the central nervous system, characterized by a heightened sensitivity to pain and other stimuli such as light, sounds and chemical substances.