Cardiovascular disease, a frontline cause of death worldwide, has some risk factors such as obesity, poor cardiorespiratory fitness (CRF), and vascular dysfunction whose primordial signs exist in childhood. Evidence suggests that excess body fat and poor CRF predict increased cardiometabolic risk and the progression of atherosclerosis. However, the mechanisms underlying vascular dysfunction with respect to predictors such as CRF, body fat, and lean mass in the young remains poorly understood.

It is unclear whether CRF in childhood and adolescence impact arterial structure and function in later life. Although several studies have assessed the influence of childhood CRF on early and or later arterial health, they are either of cross-sectional or short-term longitudinal design. Most of these studies have focused on a specific period (e.g. early or late childhood) and are restricted to a one-time measure of CRF. Moreover, inappropriate scaling measure of CRF such as not accounting for the confounding effect of body fat makes interpretation of existing evidence difficult.

Similarly, accumulation of body fat and lean mass during childhood through adolescence may significantly impact arterial health in early adulthood. But, studies that describe the physiological adaptation of vascular structure through adolescence to young adulthood in relation to increased body fat and lean mass are few. A repeated measure of CRF, body fat and lean mass is essential to determining critical periods of early life during which these factors implicate later arterial health. Evidence on suitable target ages for cardiovascular intervention, alongside unraveling the cryptic mechanisms by which CRF, body fat and lean mass relate to arterial health could be achieved. We would, therefore, assess the importance of early life exposures (e.g. CRF, body fat, lean mass, and/or endothelial function) from childhood through adolescence on vascular phenotypes between ages 9 to 24.