Evaluation of a Controlled Study on the Effects of Exercise on Physical Health in Adolescents with Overweight and Obesity: the NOW! Study

Abstract

Cardiovascular disease is one of the leading causes of death worldwide and accounts for high levels of morbidity (GBD 2021 Risk Factors Collaborators, 2024). It emerges from cardiovascular risk factors such as elevated blood pressure, overweight and obesity, low cardiorespiratory fitness and physical inactivity (Kartiosuo et al., 2024). These risk factors can already induce subclinical vascular changes during childhood which track into adulthood and may lead to manifest cardiovascular disease later in life (Bao et al., 1995; Hauser et al. 2023; Lindberg et al. 2020). Physical inactivity is an established modifiable risk factor for cardiovascular disease, contributing to increased cardiovascular morbidity and mortality across the lifespan (GBD 2021 Risk Factors Collaborators, 2024). However, many children and adolescents do not reach the recommended amount of physical activity and are overweight or obese (Guthold et al., 2020). This highlights the urgent need for evidence-based, targeted interventions aimed at enhancing physical activity levels and preventing excessive weight gain in this population. We therefore aim to assess the effects of a one-year exercise intervention on vascular health and cardiovascular risk factors in children and adolescents with overweight and obesity. The objectives of this controlled study are: 1) to analyze the effect of a one-year structured exercise intervention in children and adolescents with overweight or obesity on their vascular health, as measured by retinal vessel diameters using static retinal vessel analysis, and 2) to analyze if a one-year structured exercise intervention in children and adolescents with overweight or obesity will lead to a reduction in body fat percentage, a decrease in systolic and diastolic blood pressure, and higher cardiorespiratory fitness. In this controlled intervention study based on the now! project, each of the three cohorts consists of 56 adolescents aged 12 to 14 years in the intervention group undergoing a structured exercise intervention and 28 adolescents in the control group. They will be screened for anthropometry, blood pressure, retinal vessel diameters, maximal strength assessment, cardiorespiratory fitness, cognition and lifestyle assessments. The relevance of this study lies in addressing modifiable cardiovascular risk factors in children with overweight and obesity through a structured exercise intervention and in evaluating their vascular health using retinal vessel analysis, a sensitive marker for early microvascular alterations. These findings will provide valuable evidence to support long-term promotion of exercise aimed at preventing the development of cardiovascular disease in children and adolescents, including integration into cantonal physical activity promotion strategies with low-barrier accessibility and potential nationwide scalability.

References

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