Application of the social cognitive theory to an electronic activity monitor system-based Physical Activity Intervention for working adults

  • Ka Man Tam

Student thesis: Doctoral Thesis


Adults in Hong Kong show relatively low participation in physical activity. In the wake of technological advancements, it has become necessary to promote physical activity in an innovative approach. To that end, this study aimed to investigate the effect of an application of Social Cognitive Theory (SCT) under an eight-week electronic activity monitor system (EAMS)-based intervention on changes in physical activity (PA) as well as its associated SCT constructs of self-efficacy, social support and self-regulation for working adults in Hong Kong. A series of studies were performed: Study 1: In order to assess the validity of the step count output of two popular electronic activity monitor system (EAMS) model, Fitbit Charge HR and Xiaomi Mi Band 2, healthy adult (N=30) worn both EAMS and walked at five predetermined speeds on a treadmill. Two-factor (step x speed) repeated measures ANOVAs was performed to compare the output of devices with manual step count. Result: there was no significant mean difference (p> 0.05) in step count among the Fitbit Charge HR and Mi Band 2 activity monitors and the criterion in all treadmill speeds. Both of them are valid devices for step count in the laboratory setting. Study 2: As to assess the validity of step measurement of Mi Band 2 in the free-living environment, 31 healthy adults were invited for wearing both Mi Band 2 and ActiGraph GT9X Link on their dominant hands wrist for 7 consecutive days. Paired sample t-tests and Pearson correlation were conducted to compare the average steps per day between Mi Band 2 and ActiGraph GT9X Link. Result: there was no significant mean difference (p >0.05) and high positive correlation in step count between the Mi Band 2 and Actigraph. The Mi Band 2 is a valid device for step count in the free-living environment. Study 3: To examine the validity and reliability of the Chinese version of PA related self-efficacy, self-regulation and social support in Hong Kong Chinese adults. There were 230 healthy adults aged 19-63 years recruited. The factorial validity of the scales was assessed by the Confirmatory Factor Analyses (CFA) while criterion validity was assessed by correlating measured constructs with self-reported PA. The internal consistency and scales test-retest reliability were evaluated by Cronbach's alpha and intraclass correlation coefficient, respectively. Result: indicators of CFA supported the one-factor structure while all PA correlates were significant (p
Date of Award26 Feb 2020
Original languageEnglish
SupervisorSiu Yin CHEUNG (Supervisor)

User-Defined Keywords

  • Social cognitive theory
  • Exercise
  • Physical fitness
  • Electronic measurements

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