Consensus process for measuring physical activity started in June 2006

Based on earlier attempts for harmonisation, such as EUROFIT, EUPASS, IPAQ, and WHO GPAQ, a new consensus process for instruments to assess physical activity started in June 2006. In order to measure how active European citizens are and how much it benefits their health, standardised instruments are needed. In people’s day-to-day life, there are four domains, which provide opportunities to be physically active: at work, for transport, in domestic duties, or in leisure time (WHO, 2002d). Furthermore, 4 characteristics of people’s activity need to be measured in order to estimate the resulting health benefits: frequency, intensity, time and type of activity.

Questionnaires are the most cost-effective measuring method

Questionnaires are a cost-effective, but subjective way of assessing the characteristics of peoples activity. Mainly 2 initiatives developed questionnaires in the last decades: (1) the International Physical Activity Questionnaire (IPAQ, initiated by a consortium of scientific and health institutions around the world) and (2) the Global Physical Activity Questionnaire (GPAQ, as part of WHO’s Global Physical Activity Surveillance activity, especially in developing countries), which derives from IPAQ. Difficulties in applying questionnaires in a standardized manner arise from differing cultural and linguistic backgrounds (e.g. the translation process or cognitive testing of which meaning is associated with the questions) as well as the difficulties in administering questionnaires to different age groups (e.g. answers from children seem to be much less reliable). Furthermore, domain specific questions for assessing the activity promoting or preventing characteristics of the built environment, for assessing physical activity at the work place as well as during daily transportation need agreement.

Accelerometers and health related fitness tests are an objective measurement method

Accelerometers are an objective measurement, using small devices comparable to common pedometers for monitoring people’s vertical movements (by walking, running, etc.) over days or weeks. With decreasing costs of these devices in the last decade, accelerometry develops as a useful alternative to questionnaires (EC, 2007b).

Health-related fitness tests are also an efficient way of assessing people’s fitness and a consensus about which test is most reliable and feasible in large samples needs to be accomplished.

Data collection and interpretation need to be standardized

To gain comparable data, for all these instruments and options, data collection and interpretation routines need to be standardized and subsequently applied. The project Assessing levels of phyiscal activity and fitness (ALPHA) with involvement of the European Commission, WHO, CDC and academic centres around the world started this consensus process in June 2006.