Hidde van der Ploeg is a senior researcher with the Department of Public and Occupational Health of the VU University Medical Center. He is also an adjunct senior research fellow with the Sydney School of Public Health of the University of Sydney (Australia). He holds a PhD (2006) and degrees in Epidemiology and Human Movement Science (major in exercise physiology and minor in psychology) all from the VU University Amsterdam in the Netherlands. His main research expertise is in physical activity and sedentary behaviours in relation to public and occupational health. His main focusses are on 1) physical activity and sedentary behavior interventions in health care and workplace settings, 2) the measurement and surveillance of physical activity and sedentary behaviours.