Background: The increase in the global population has placed extra burdens on health services. This is due to the increased risks of cardiovascular disease, with more people falling into the overweight and obese categories. Developed public health interventions prevent risks of health complications, promoting healthier lifestyles and prolonging the quality of life. Those motivated adopt new methods to become healthier. On the other hand, those less motivated are at risk of being overweight and leading a sedentary lifestyle. In 2014, the World Health Organisation (WHO) established that non-communicable diseases were the leading cause of global deaths. Aim: This systematic review critically evaluates the effects of physical activity interventions in adults (18–65 years), and the impact on risk factors of cardiovascular diseases and obesity. Methods: Nineteen items of literature published between 2000 and 2016 were examined using quality of assessment tools. These provided a greater understanding of the effectiveness of physical activity interventions. Outcomes: The complexity of this topic was experienced, with many aspects (such as inter- and intra-personal factors) affecting the effectiveness of physical activity interventions. It was noted that continuous support should be provided during the intervention period, motivating participants by increasing engagement through peer support and group activities, providing long-term sustainability of the willingness to adopt lifestyle changes. Further recommendations examining quantitative data analysis were suggested, exploring how physical activity intensity affects the risks of metabolic syndromes. Social behaviour and its effects on food consumption was also highlighted for further research, enhancing future public health interventions. |