New technology provides opportunities to accurately measure physical activity, physical fitness, and sedentary behaviour. Improved measurement is needed to: 

• assess the scale of the problem of low physical activity 
• understand the health effects of physical activity 
• evaluate the effect of interventions to more physical activity and less sedentary behaviour 
• understand secular trends in physical fitness 
• evaluate the effects of interventions intended to improve physical fitness 

Examples of our work on this area include: 

• Objective measurement of the 24-hour movement behaviours (physical activity, sedentary behaviour and sleep) in the under 5s, children and adolescents - Professor John Reilly
• Integration of objective measurement of behaviour (e.g. sedentary behaviour) and health outcomes (e.g. glucose) - Dr Alison Kirk, Dr Katy Weston, Dr Fiona Muirhead  
• Pragmatic evaluation of school, family and community-based interventions - Dr. Deirdre Harrington 
• Physical fitness assessment, monitoring and surveillance in children and adolescents - Dr Katy Weston, Professor John Reilly