The Transtheoretical model’s processes of change in the heart of a physical activity intervention : a series of n-of-1

Abstract

Objective: The objectives were a) to test whether a Processes of Change (POC)-personalized Transtheoretical model (TTM)-based intervention could increase physical activity (PA) among inactive adults, and b) to examine whether the intervention increased the level of TTM theoretical constructs. The following hypotheses were formulated: 1) PA levels will be significantly higher during and after the intervention in comparison to baseline measures; 2)the level of targeted POCs will significantly increase during the intervention; 3) non targeted POCs will stay stable, and 4) SE and DB levels will significantly increase during the intervention. Method: A series of N-of-1 with A (1 to 2-week)-B (10-week)-A’(2-week) design were conducted with 12 inactive adults. Behavioral counselors used behavior change techniques to target TTM constructs and supervise PA. Interventions were individualized based on the 5 POCs with the lowest pre-intervention level. PA was evaluated using an accelerometer and via an agenda. TTM measures were weekly collected online. PA data were analyzed with piecewise linear models. A visual analysis was run to examine the TTM constructs. Results: Device, self-reported and TTM data were available for five, seven and five participants, respectively. A significant self-reported PA increase for six participants was found during the phase B and A2. A significant device-measured PA increase was observed in two participants during the study. A substantial increase of targeted POC from baseline for all participants with available data was observed. Conclusion: This study provides the first evidence of behavioral and psychological effects of a POC-personalized TTM-based intervention in inactive adults.

Dynamic Patterns of Personality States, Affect and Goal Pursuit Before and During an Exercise Intervention: A Series of N-of-1 Trials Combined with Ecological Momentary Assessments

“…Exercising has been associated with various health outcomes such as physical and mental health. While interventions to increase physical activity levels have mainly been focusing on group interventions (Burke et al, 2006), a better understanding of the individual psychological characteristics show a promising avenue to develop successful and durable individualized interventions, particularly when studied at the daily level (Lapointe et al, 2023). Indeed, psychological effects of physical exercise were examined with a pre-and postassessments in most of previous interventional studies.…”