Effect of a physical activity improvement program using the transtheoretical model at a small-scale company.

The present study aimed to investigate the potential use of the transtheoretical model (TTM) by clarifying the program's effects on workers at a small-scale company. Subjects were 22 male workers at a communication system company. They were divided into two physical activity improvement program groups, the TTM-based assistance group (TTM group, n=12) and the control group (n=10). During the study period each subject was asked to wear a calorie counter and to record daily exercise. Changes in number of steps per day and body weight were measured before, immediately after, and 1 month after the intervention ended. Stage of exercise behavior, health protective behavior, and self-efficacy were also examined by means of self-administered questionnaires. In the control group, the number of steps per day tended to increase immediately after the intervention and then decreased at 1 month after the program ended. In both groups, physical activity peaked during commuting and lunch hours. This peak persisted for 1 month after the intervention in the TTM group, but not in the control group. Moreover, the stage of exercise behavior tended to progress in the TTM group, whereas regression in the stage of exercise behavior was observed in the control group. In the control group, although the exercise self-efficacy score after intervention was higher than that before intervention, the health protective behavior score decreased at 1 month after the program ended. This study suggested that physical activity improvement programs based on TTM may be useful for workers at small-scale companies. However, further study of larger numbers of workers will be needed to confirm the validity and usefulness of these results.