We employed the Health Belief Model (HBM) as a theoretical lens to explore the influence of an exercise intervention on the perceptions and knowledge of modifiable risk factors for non-communicable diseases (NCDs) among women from a low-resource setting in South Africa. We used a mixed-methods design, gathering qualitative and quantitative data at baseline (n = 95) and again after 12 weeks (n = 55) and 24 weeks (n = 44) of an exercise intervention. Qualitative data consisted of focus group discussions exploring the knowledge and perceptions of modifiable risk factors for NCDs at the three time points. We collected quantitative measurements of modifiable risk factors for NCDs (waist-to-hip ratio, body mass index, blood pressure, peripheral blood glucose, and cholesterol) as well as objective physical activity (PA) data over seven consecutive days. Surveys on coronary heart disease and PA knowledge were conducted at all three time points. Qualitative findings indicated that health exposures and cultural traditions influenced the participant’s perceptions about PA and NCDs. Waist circumference significantly decreased at 12 weeks compared to baseline MD = 4.16, p < 0.001. There was significant improvement at 12 weeks, compared to baseline, MD = 0.59, p = 0.009 for PA knowledge, and MD = 0.68, p = 0.003 for heart disease knowledge. There were reductions from baseline to 24 weeks in diastolic blood pressure (MD = 4.97, p = 0.045), waist circumference (MD = 2.85, p = 0.023) and BMI (MD = 0.82, p = 0.004). Significant heart disease knowledge improvements were found at 24 weeks compared to baseline (MD = 0.75, p < 0.001). Supervised exercise positively influenced Black African females′ health behaviours by understanding cultural perceptions of modifiable risk factors for NCDs.
Keywords: Black South Africans; Health Belief Model; knowledge and perceptions; mixed methods; non-communicable diseases; physical activity; supervised exercise.