His primary area of research is physical activity and public health. Prof. Hallal has published more than 500 scientific articles and his research has been funded by Brazilian and international agencies. According to Google Scholar, Prof. Hallal's work has been cited >74,000 times, and my h-index is 107. Prof. Hallal was the leader of the 2012 Lancet Physical Activity Series and steering committee member of the 2016 and 2021 series – work that informs the global health burden of physical inactivity. He is one of the founders and former president of the Brazilian Society of Physical Activity and Health. He serves as the Editor-in-Chief of the Journal of Physical Activity and Health. More recently, Prof. Hallal served as the Principal Investigator for the EPICOVID19 project, the largest epidemiological study on Covid-19 in Brazil.