Background: It is not well understood how sedentary women who wish to engage in regular exercise adhere to interventions during pregnancy and what factors may influence adherence over time.
Objective: The aim of this study was to examine longitudinal patterns of pregnant women's adherence to exercise.
Methods: Exploratory secondary data analyses were carried out with 124 previously sedentary pregnant women (ages 31 ± 5 years; 85% non-Hispanic White) from a randomized controlled trial. Daily exercise logs (n = 92) from 18 through 35 weeks of gestation were explored using linear regression, functional data, and principal component analyses.
Results: Adherence decreased as gestation week increased (p < .001). The top adherers maintained levels of adherence, and the bottom adherers decreased levels of adherence. And adherence pattern was influenced by types of exercise throughout the study period.
Discussion: Exercise behavior patterns were explored in a randomized controlled trial study, using chronometric data on exercise attendance. A new analytic approach revealed that sedentary pregnant women may adopt exercise habits differently from other populations.