**5. Physical activity as a public health intervention**

Public health covers both illness prevention and promotion of personal wellbeing. Today's public health requires an inter- and multi-disciplinary team of public health workers that can implement a variety of preventive and/or responsive interventions, including epidemiology, outreach, screening, health teaching, social marketing, and policy development. Due to physical activities ability to contribute to numerous spheres of public health, it has become an integral component of public health systems [36, 37].

Research in the physical activity adherence has resulted in the recognition of several methods to influence an uptake of physical activity at the individual level [38]. However, the considerable prevalence of inactivity across most sectors of the global population necessitates higher-level approaches to physical activity promotion that include environmental, organisational, and policy-level strategies.

Physical activity provides an ideal population-wide public health intervention due to it efficacy and its low-cost ideally suited to the limited resource environment public health decision makers frequently find themselves in [39]. In this regard, many physical activity interventions require little/no equipment, require minimal supervision (in those without high risk), and can be delivered in community settings. Further, many health professionals such as physiotherapists, Biokineticists, and exercise physiologists are already serving in communities and at a population level in many countries, including low- and middle-income countries (LMICs) [40]. Where communities and countries exist that do not have such professionals specifically trained in physical activity, there is opportunity for roles and training for physical activity awareness and prescription to be offered to other healthcare professionals, such as public health practitioners, and nurses, already well placed in communities, at schools, and at a population level.

It is important to understand how physical activity affects the whole ecology. In this regard, physical inactivity and its associated morbidity and mortality affects the home, school, and workplace. It is this pervasive importance that should ensure that physical activity considerations be utilised in local strategy, policy and planning and enhancements to the built or natural physical environment to improve public spaces, workplaces, and schools to boost and provide individuals of all sectors, ages, and abilities access to physical activity.

Physical activity is imperative at a local community level due to its significant impact on physical and mental wellbeing. Determining methods for individuals in communities to enjoy physical activity can encourage regular physical activity participation. This can be achieved by prioritising pedestrians, cyclists and individuals who utilise public transport, involving community members in creating and managing public spaces [41].

Limited evidence exists to demonstrate the most appropriate methods to enhance physical activity in young children, especially considering declining school participation in sports and removal of physical education programmes [42]. However, the inclusion of parents in public health initiatives to perform parental goal setting with their children regarding physical activity have been found to be successful. Further,

parental monitoring, having physical activity training providers, and encouraging healthy role-modelling in schools could increase children's levels of physical activity and could lead to healthier familial and school environments. This increase in physical activity is especially important in that being active in childhood has unequivocally been shown to encourage physical activity participation into adulthood [41].

The workplace presents an ideal setting to promote and deliver physical activity initiatives. This is because physical activity in the workplace provides the opportunity to overcome one of the most common barriers to regular physical activity namely a 'lack of time'. Workplace physical activity programmes also provide access to physical activity to a large portion of society [43]. Apart from the long-term physical and mental health benefits associated with physical activity, when physical activity is promoted in the workplace it has been shown to decrease conditions that contribute to absenteeism associated with illness, improve productivity and staff retention, decrease the costs for employers, and increase loyalty [41].
