Methodologische Herausforderungen in der Erfassung körperlicher Aktivität: Implikationen für Wissenschaftspraxis und Forschung

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The precise measurement of physical activity forms the basis for the investigation of dose-effect relationships and the actions derived from them in movement-oriented prevention and rehabilitation. In the course of time, various measuring instruments have been developed for this purpose. However, they differ in the way physical activity is recorded and thus have different strengths and weaknesses in terms of validity and applicability. The present cumulative dissertation therefore investigates the question of whether there is further potential for improvement within the operationalisation of physical activity. To answer this question, three studies were conducted:
Study No. 1 used a review to examine the methodical basis of current findings on effective physical activity promotion interventions in the adult population. It turned out that the majority of the 33 included intervention studies had a high-quality study design in the form of randomised controlled trials, but in most cases, they mainly used questionnaire data for the operationalisation of physical activity - especially in studies with large sample sizes. Accelerometry, which is considered to be a more valid measurement tool for recording physical activity volumes and intensities, is primarily used in studies with fewer than 100 subjects. Due to the frequent use of questionnaires, which are considered to be less valid, the results indicate that further research is needed in order to confirm the previous findings on physical activity with more valid measuring instruments. At the same time, the limited use of accelerometry indicates that there is a challenge in terms of applicability that needs to be overcome.
Study No. 2 used a two-week crossover study (n = 54; 57.4% female; 28.3 ± 12.2 years old) to examine the effects of pictorial representations (show cards) of physical activity on the precision of self-reports in the Global Physical Activity Questionnaire (GPAQ). While one group answered the GPAQ with the show cards (GPAQ+) after the first week and one week later without the show cards (GPAQ-), the procedure was reversed for the second group. In comparison with the respective data collected using accelerometry (Actigraph GT3X+), no statistically significant difference between the two GPAQ versions could be identified. The differences to the accelerometry data ranged between 21.2 and 35.2 min/day for both versions regarding moderate and vigorous physical activity. Furthermore, both GPAQ versions show similar correlation coefficients to accelerometry regarding vigorous physical activity (rho = 0.31-0.42). Accordingly, no positive effect of the show cards on the precision of the questionnaire data could be detected. Instead, the data point to the discrepancy between the different measurement methods.
Study No. 3 examined the influence of the recruitment method on the applicability of accelerometry in terms of the resulting sample and data. For this purpose, two different recruitment methods of two primary studies on the promotion of physical activity in vocational schools were compared. In the active recruitment group (AR; n = 30; 73.3% female; 21.8 ± 5.2 years old), subjects of the primary study could volunteer for additional accelerometry. In the passive recruitment group (PR; n = 52; 53.4% female; 20.5 ± 2.9 years old), consent to accelerometry was given in line with consent to participate in the primary study. With regard to the resulting samples as well as the resulting activity data, no significant differences between the recruitment procedures could be found. Both groups showed only moderate adherence to accelerometry. Thus, AR and PR are comparably applicable at least in the vocational school setting, but a much higher population needs to be addressed for AR in order to recruit a comparable sample size for accelerometry.
While study No. 1 provides an overview of current scientific practice, studies No. 2 and 3 examined possible potential for improvement with regard to the validity and applicability of questionnaires and accelerometry. As a result of these three studies, it can be stated that current scientific practice in the field of physical activity promotion has still much potential for improvement. In addition to an improvement in reporting data outcomes, an increased use of more valid measuring instruments should be aimed for. In this context, compliance with established guidelines for the standardised use of different measuring instruments can be an approach to strengthen the informative value of questionnaire surveys and to increase the amount of data in accelerometry. Furthermore, it is necessary to look for further ways to enable a valid and at the same time practicable measurement of physical activity. In addition to the development of new measuring instruments, this includes further improvement of existing measuring systems and the combined use of different instruments.
Original languageGerman
Place of PublicationKöln
PublisherDeutsche Sporthochschule Köln
Number of pages70
Publication statusPublished - 20.10.2020

ID: 5473221

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