The predictive utility of the theory of planned behaviour for physical activity in a Malaysian population: A mixed methods approach

Participation in physical activity is a key component of a healthy lifestyle. The objectives of this dissertation were to test the utility of predicting physical activity behaviour of the Theory of Planned Behaviour (TPB) as well as self-efficacy using a specifically devised questionnaire for a Malaysian population and the Exercise Self-Efficacy Scale. This study was carried out among the Non-Governmental Organizations (NGO) receiving support from the Ministry of Health Malaysia to run physical activity programmes. To fulfil the objectives, both quantitative and qualitative methods were employed in this research. The first study used qualitative methods to develop a Malaysian TPB questionnaire. This was then used in the main study where quantitative data were collected at four time points in a longitudinal study of engagement with physical activity programmes. In addition, to gather an in-depth understanding of beliefs, qualitative data was also collected via interviews with attendees and organisers of the NGOs, as well as senior officials in the Ministry of Health Malaysia. Findings from the main study provided support for the utility of the TPB in identifying the determinants of the physical activity behaviour. Attitude emerged as the strongest predictor of behavioural intention across all time points. The study found a significant association between quality of life and physical activity, particularly of vigorous intensity. TPB has been shown to be effective in predicting physical activity behaviour among the Malaysian population. This study provides support of the relationship between performing physical activity and quality of life especially among the Malaysian population