Planned Behavior Model

Intervention
The main aim of the proposed intervention is to encourage obese pregnant women to be more physically active, in order for them to reduce their excess weight and reach a suitable weight to maintain. The Theory of Planned Behaviour model (TPB) by Ajzen, (1991) will be used to explain the intervention process – this model is one of the most validated models that predict behaviour (Downs & Hausenblas, 2004). These researchers successfully used this model and found that the most salient beliefs were that mood could be elevated by exercise and weight gain was influenced by exercise. The behavioural beliefs (attitude), normative beliefs (subjective norm) and control beliefs (perceived control) of the TPB all determine intention and
The selected will receive emails with a forwarded self-report questionnaire pre-intervention; this will ask for their current weight and then measure each of the TBP components (Ajzen, 2002); for behavioural intention there will be a scale ranging from ‘strongly disagree’ to ‘strongly agree’ whereby the women will need to place a check within one of the nine different points that best represents their intentions ‘ I plan to participate in around 30 minutes of physical activity every day for the next month. This will be followed by measures of attitude including different adjective scales ranging from ‘harmful-beneficial,’ ‘pleasant-unpleasant’ etc. ‘For me to partake in around 30 minutes of physical activity daily for a month is.’ The measure of subjective norms will include ‘Most people who are important to me think that’ and another scale ‘I should-I should not’ complete around 30 minutes of physical activity daily, for a month. Finally for perceived behavioural control – measures will include scales covering control and self-efficacy; ‘impossible-possible’ ‘For me to undergo 30 minutes of physical activity for around 30 minutes every day for a month
Comparison is necessary to ensure that changes in the 50 women attending the intervention are due to intervention participation itself and no external influences. Questionnaires will be given to all 100 of the women pre-intervention, immediately post intervention and a final one 6 weeks later to see whether the intervention had long-lasting effects for the women who took part, and compare it to the women who did not. Positive changes to attitudes, others’ beliefs and personal control beliefs will be indicative of a successful intervention effect where behavioural intentions were acted upon. Their weight and measure of BMI on each of the three occasions will determine whether they are still obese or have excess weight – a decline would suggest that the intervention was effective in reducing obese pregnant women’s excess weight. The scores from the pedometer will be calculated on the three separate occasions to see whether both groups of women continued to be physically active. A high pedometer score would imply that more physical activity had been