**4. Cardiovascular disease and resistance training across the lifespan**

While the focus of much CVD studies is on adults, it is important to recognise that CVD risk factors may develop and even begin to detrimentally affect health during in childhood and adolescence [37]. The arteriosclerotic process can begin and rapidly accelerate at an early age [38]. As with adults, CVD risk factors, and especially composite CVD scores, are strongly associated with physical fitness in children [39, 40]. This has led to several recent changes having occurred in international recommendations for children's participation in physical activity for health [39]. Research, evidence and subsequent guidelines predominantly promote the benefits of aerobic activity for children and adolescents. Again, RT has proven to be a safe exercise modality able to promote improved cardiovascular health in children. Despite some research indicating that the beneficial effects from RT interventions are sometime modest [39], RT can supply additional, unique benefits to the health and functional capacity of children in particular. These benefits can be realised over and above those from aerobic exercise [40]. In this regard, low muscle strength has been independently associated with a poorer metabolic profile during adolescence [41]. In addition, increasing evidence is arising indicating that concurrent training programmes utilising both aerobic and RT components display additive or crossover effects of both modes of training when compared to a single mode of exercise alone, even in children [40]. It is for this reason that the promotion of physical activity, including RT, should be a critical element in public health policy to prevent the onset of CVD later in life [39, 42]. This is because childhood provides an excellent window of opportunity to educate children about healthy lifestyle habits and cardiovascular health, rather than to attempt to re-programme well-established unhealthy behaviours in adults.

Despite some developed countries, such as the United Sates of America, seeing an overall reduction in CVD mortality, CVD mortality is on the rise in younger women [43]. This is because in addition to an increasing prevalence of CVD risk factors, women display several clinical conditions or sex-specific CVD risk factors, such as pre-eclampsia, gestational diabetes, polycystic ovary syndrome, early menopause and autoimmune diseases that have been shown to increase the development of CVD [43, 44]. Although great strides have been made regarding CVD mortality in women, not all women are benefitting equally from CVD-related mortality reduction. In this regard, women could gain significant cardioprotective benefits from engaging in RT. This is because RT has been proven safe for use in women and has a unique ability to maintain or increase muscle mass [45, 46] and may offset their lower muscle mass and higher fat mass when compared to men [47]. Individuals with high muscle mass, especially when combined with low fat mass display the lowest mortality risk compared with other body composition subtypes [48, 49]. Women's lower muscle mass when combined with their average 40% less upper-body strength and 33% less lower-body muscle strength and their effect on mortality [50], calls for the specific inclusion of RT as part of any guideline-directed, evidence-based, and sex-specific management and treatment recommendations aimed at improving CVD outcomes in women.

Age also plays a critical role in the deterioration of cardiovascular function, and it is for this reason that risk and prevalence of CVD both increase with age [51, 52]. Increases in CVD in older adults can be linked to functional changes in the ageing heart (i.e. diastolic and systolic dysfunction) and/or electrical dysfunction (i.e. arrhythmias) and other CVD risk factors, such as inflammation, oxidative stress, apoptosis and degeneration [52, 53]. This degeneration is as a result of a significant loss of muscle mass or sarcopenia that is one of the hallmarks of ageing. Without
