Her research has primarily focused on understanding, measuring and influencing physical activity and sedentary behaviour. She has demonstrated skills in a range of study designs, including development and validation of measurement methods, systematic review and meta-analyses, feasibility and acceptability trials, randomised controlled trials and cross-sectional and longitudinal analyses of large data sets. She has developed and evaluated several methods of measuring physical activity, including both consumer and research device based methods as well as self-report methods using a use of time approach. Sjaan has assessed physical activity and developed and evaluated physical activity interventions across a broad range of populations and settings including physically inactive adults, working adults (shift workers and truck drivers), adults living with and beyond cancer, adults with chronic disease (cardiovascular disease, non-alcoholic fatty liver disease, metaboloic syndrome), adults with overweight or obesity, adult wheelchair users, children with chronic respiratory disease and children with obesity. She has a strong track record for multi-disciplinary collaborations with national and international collaborators in health and rehabilitation sciences, public health, clinical exercise physiologists, exercise science and nutrition. Sjaan is a passionate advocate for physical activity and is committed to striving for translation of evidence into clinical practice in healthcare settings.