Factors determining physical activity of emerging young adults: a mobile-based Ecological Momentary Assessment (mEMA) study

Abstract

Background: Carrying out sufficient amounts of physical activity (PA) is difficult for many emerging young adults. Therefore, the primary objective of the present mobile-based Ecological Momentary Assessment (mEMA) study was to gain a better understanding of the underlying motivational (cognitive and affective) and contextual (physical and social environmental) determinants of walking, cycling, and exercising, and to find out when these effects occur. Methods: Over the course of seven consecutive days, 71 participants (64% female) received prompts from the mEMA-app four times a day, containing questions regarding cognitive (i.e., intention, perceived behavioral control, perceived environment), affective, and contextual factors (i.e., physical and social environment) that may have influenced their PA during the previous 3.5 hours. Multilevel analyses (i.e., time of day nested within individuals) and exploratory timelagged analyses were conducted. Results: PA behaviors were associated with mood (e.g., walking (ORfeelinglively = 1.7, 95% CI 1.05-2.87), the physical setting (e.g., cycling (ORschoolsetting = 1.8, 95% CI 1.02-3.18), and the social environment (e.g., exercise (OR = 1.8, 95% CI 1.06-3.19). Time-lagged analyses revealed that although intention and PBC were not directly associated with PA, they did predict subsequent PA (e.g., exercise (ORintention T+1 = 2.7, 95% CI 1.56-4.60). Conclusions: Although contextual factors are related to concurrent PA behaviors, motivational factors (intention, PBC and affect) determine subsequent PA behaviors. Therefore, it is important to note that cognitive factors and behaviors fluctuate over time, which may explain differences in relationships between cognitions and PA behaviors as shown in previous cross-sectional studies.