Objective: The aim of this study was to analyse the effect of an Internet-based motivational intervention (IMI) supported by pedometers (in comparison with IMI alone and non-intervention) on increasing daily steps and changing constructs related to physical activity (PA) in a sample of sedentary students.
Design: A randomised-controlled trial was conducted with 76 sedentary or low-active college students. The purpose of the IMI was to deliver information to increase motivation and set individualised PA goals. It involved a 3-week intervention and a 3-months follow-up.
Outcome measures: Objective measures were used to measure daily steps, and self-report questionnaires to assess different constructs related to PA.
Results: Results revealed that IMI supported by pedometers condition increased significantly more the daily steps (post-intervention: M = 2069; SD = 1827; follow-up: M = 2227; SD = 2477) and enjoyment than non-intervention condition at both points in time. Moreover, results showed that IMI alone condition increased more the scores in variables involved in PA behaviour than non-intervention condition.
Conclusions: This study shows the effectiveness of a self-administered IMI using pedometers in increasing PA and enjoyment, and the effectiveness of the IMI alone in changing different theoretical constructs related to the PA behaviour.
Keywords: Internet; motivational intervention; pedometer; physical activity; randomised control trial.