ICAD_logoObjective methods, such as accelerometers, have become a preferred option when measuring population levels of physical activity, examining trends in activity patterns and when examining associations between activity and health outcomes in young people.

The International Children’s Accelerometry Database (ICAD) project is a consortium including 20 partners which pooled and reduced raw accelerometer data using standardized methods to create comparable outcome variables in 32,000 young people aged 3 to 18 years across studies from Europe, the US, Brazil and Australia.

By pooling and reanalysing accelerometer data from different studies the ICAD has the potential to; a) increase statistical power due to a large sample size, b) create a more heterogeneous and potentially more representative sample, c) standardize and optimize the analytical methods used in the generation of outcome variables, and d) provide a means to study the causes of inter-study variability in physical activity.

The ICAD project was funded by the National Prevention Research Initiative in the UK and is led by a steering committee including representatives from MRC Epidemiology Unit (Prof. Ulf Ekelund, Dr. Esther van Sluijs), University of Bristol (Prof. Ashley Cooper, Dr. Angie Page), Loughborough University (Dr. Lauren Sherar, Dr. Dale Esliger) and Norwegian School of Sports Scineces (Prof. Ulf Ekelund).

The database is managed by the MRC Epidemiology Unit and is publicly available for data requests.

Applying to use ICAD data

The ICAD is open for data request as a supported access rescource. Please find information regarding the application process to access the data below. Data will be released in chronological order by date of accepted proposals and usually within 5 to 10 working days. Please contact Dr Lauren Sherar with data requests using the application form below:

Publishing and presenting ICAD Data

Additional material

ICAD papers

  • Hildebrand M, Kolle E, Hansen BJ, Collings PJ, Wijndaele K, Kordas K,  Cooper AR, Sherar LB, Andersen LB, Sardinha LB, Kriemler S, Hallal P, Van Sluijs E, Ekelund U. Association between birth weight and objectively measured sedentary time is mediated by central adiposity: data in 10,793 youth from the International Children’s Accelerometry Database. Am J Clin Nutr, 2015, Published Online Apr 2015 [full text]
  • Brazendale K, Beets MW, Bornstein DB, Moore JB, Pate RR, Weaver RG, Falck RS, Chandler JL, Andersen LB, Anderssen SA, Cardon G, Cooper A, Davey R, Froberg K, Hallal PC, Janz KF, Kordas K, Kriemler S, Puder JJ, Reilly JJ, SAlmon J, Sardinha LB, Timperio A, van Sluijs EMF, on behalf of the International Children’s Accelerometry Database (ICAD) Collaborators. Equating accelerometer estimates among youth: the Rosetta Stone 2. J Sci Med Sports, 2015, Published Online Feb 2015 [full text]
  • Goodman A, Page AS, Cooper AR; International Children’s Accelerometry Database (ICAD) Collaborators. Daylight saving time as a potential public health intervention: an observational study of evening daylight and objectively-measured physical activity among 23,000 children from 9 countries. Int J Behav Nutr Phys Act, 2014, Oct 23;11:84.[full text]
    For press coverage, please see for example: BBC, Guardian
  • Atkin AJ, Sharp SJ, Corder K, van Sluijs EM; on behalf of the International Children’s Accelerometry Database (ICAD) Collaborators. Prevalence and correlates of screen time in youth: an international perspective. Am J Prev Med, 2014 Sep 16 [full text]
  • Kwon S, Janz KF; International Children’s Accelerometry Database (ICAD) Collaborators. Tracking of accelerometry-measured physical activity during childhood: ICAD pooled analysis. Int J Behav Nutr Phys Act, 2012; 9:68 [full text]
  • Ekelund U, Luan JA, Sherar LB, Esliger DW, Grew P, Cooper A. Moderate to Vigorous Physical Activity and Sedentary Time and Cardiometabolic Risk Factors in Children and Adolescents. JAMA, 2012; 307: 704-712 [full text]
  • Sherar L, Griew P, Esliger D, Cooper A, Ekelund U, Judge K, Riddoch C. International children’s accelerometry database (ICAD): Design and methods. BMC Public Health, 2011 [full text]

Studies that have contributed data


NHANES (wave 2003/2004 and 2005/2006)

Project TAAG (Trial of Activity for Adolescent Girls)

– CHAMPS US (Physical Activity in Pre-School Children)

Iowa Bone Development Study


– 1993 Pelotas Birth Cohort


– European Youth Heart Study (Norway, Portugal, Estonia and Denmark)

PEACH Project (Personal and Environmental Association with Children’s Health)

– Project MAGIC (Movement and Activity Glasgow Intervention with Children’s Health)

ALSPAC (Avon Longitudinal Study of Parents and Children)

SPEEDY (Sport Physical Activity & Eating Behaviour: Environmental Determinants in Young People)

– CHAMPS UK (Children’s Health and Activity Monitoring Program)

– The Copenhagen School Children Intervention Study

– Belgium Pre-school Study

– Swiss Ballabeina Study

– Swiss Kinder-Sportstudie (KISS) Study


– Project CLAN (Children Living in Active Neighbourhoods)

– Project HEAPS (Healthy Eating And Play Study)