Modeling Longitudinal Relationships Between Habit and Physical Activity: Two Cross-Lagged Panel Design Studies in Older Adults.

These longitudinal studies in older adults targeted mediated relationships between habit and physical activity (PA). In The Netherlands two independent studies were conducted among 1976 (Study 1: Mage = 63.63, SD = 8.66, 30% functional limitations) and 2140 (Study 2: Mage = 62.75, SD = 8.57, 45% functional limitations) adults aged 50 years or older. Cross-lagged panel designs were applied to examine whether habit mediates the relationship between prior and later PA and whether PA simultaneously mediates the relationship between prior and later habit. Data on habit and PA were collected by means of questionnaires at baseline (t0) and at 6 (t1) and 12 (t2) months after baseline measurement. Results of structural equation modeling analyses were not unambiguous. Indications for the existence of both hypothesized mediation effects were found, but no clear, unequivocal pattern appeared. Somewhat more support was found for the PA-habit-PA path than for the habit-PA-habit path. More research is needed to draw more definitive conclusions.