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Physical activity measures in the 1970 British Cohort Study

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Learn about the 1970 British Cohort Study (BCS70) and its measurement of physical activity

Longitudinal study description

The BCS70 began as The British Births Survey and was later renamed Child Health and Education Study before settling on its current name. The initial birth survey involved 17,198 babies born in a single week in April in 1970. Like the older NCDS study, it was initiated with a strong focus on child health, before later including many other areas such as social, psychological, educational and economic outcomes. A total of ten main sweeps of data collection have been carried out (as of the time of writing), with follow-ups after the birth survey at ages 5, 10, 16, 26, 30, 34, 38, 42 and 46y. In childhood, parents were main reporters on their children, with teachers also providing information, in addition to child tests and school medical examinations.

Study members themselves first completed questionnaires at age 16y, and in adulthood they participated through in-person or telephone interviews, or postal surveys. The most recent BCS70 sweep (at the time of writing), which included a full range of biomeasures, was completed in 2018 at age 46-48y and achieved a total of 8,581 participating study members. Also at the time of writing, data collection at 50y was being planned [102].


Physical activity overview (5 to 42y)

BCS70 contains childhood and adult self-reported measures across physical activity domains (from 5-42y). Leisure time was measured at ages 5, 10, 16, 30, 34, and 42y; active travel was measured at age 34y; domestic activities were measured at age 16y; and sedentary behaviour measured at ages 5, 10, 16, and 42y.

In terms of comparability across sweeps in this longitudinal study, overall engagement in leisure time can be compared across ages 5, 10, 16, 30, 34, and 42y while intensity can be compared across ages where information was collected on specific activities/sports (i.e. ages 30, 34, 42y). Additional questions with frequency and duration responses varied somewhat between questions. Active travel and domestic activities were only measured at one age each and therefore cannot be compared across sweeps. Finally, sedentary behaviour provided comparable measures of duration (hr/day) in childhood and adulthood (ages 5, 10, 16 and 42y).

Additionally, objective measures of activity expenditure (kJ/kg/day) were captured at ages 46-48y using the ActivPal accelerometer (PAL technologies Ltd, Glasgow, Scotland).


Data access

BCS70 data are freely accessible to bona fide researchers by applying through the UK Data Service. More information on BCS70 is available on the CLS website.


Learn about the other studies covered by this guide and their measurement of physical activity:

Explore the measures by physical activity domain and their cross-study comparability:

Further information:

This page is part of the CLOSER resource: ‘Physical activity across age and study: a guide to data in six CLOSER studies’.