Adolescent athletes’ cardiovascular system may adapt to increased cardiorespiratory fitness by increasing blood pressure, arterial stiffness and heart growth, a new study shows. The study was conducted in collaboration between the Technical University of Munich and the University of Eastern Finland, and the results were published in the American Journal of Physiology-Heart and Circulatory Physiology.
The long-term cardiovascular impact of engaging in vigorous and competitive sports among teenagers has received little attention, because clinical endpoints and diseases are rare in the paediatric population.
In the present study, 142 paediatric athletes from the Munich Cardiovascular Adaptation in Young Athletes (MuCAYA) study who visited a sport clinic assessment at the Technical University of Munich in Germany were followed up for one year. These athletes had a gold-standard assessment of aerobic fitness with a gas-analysed bicycle ergometer fitness test, echocardiography of cardiac structure and function, and vascular assessments of arterial stiffness, central systolic blood pressure and carotid intima-media thickness were repeatedly measured at baseline and at follow-up.
The aerobic fitness level of the paediatric athletes was high, and it increased within one year. However, this increase was paradoxically associated with increased cardiac mass also known as ventricular hypertrophy, as well as increased central blood pressure, arterial stiffness and carotid intima-media thickness – changes that are usually not considered beneficial for cardiovascular health. For example, excessive heart enlargement is considered a risk factor for cardiac failure in adulthood. Accounting for factors such as age, sex and body mass index did not significantly alter the results.
“Our study shows that children and adolescents who are highly active benefit from increased endurance and fitness. At the same time, their cardiovascular system adapts in ways that are not yet fully understood and may have long-term effects on blood pressure, vascular stiffness and heart structure. These findings highlight that intensive physical activity in youth triggers complex physiological adaptations and that it is important to study these processes in more detail to best support the health of physically active children and adolescents,” says the lead author of the study, Dr Lisa Baumgartner, from the Technical University of Munich in Germany.
“These findings also emphasise how important it is to carefully monitor young athletes. While children and adolescents gain many benefits from sports, intensive training can place noticeable strain on the cardiovascular system. For us in preventive paediatrics, this means close medical supervision and regular check-ups are essential to identify potential risks early. Only in this way can young athletes fully enjoy the benefits of sports without compromising their long-term heart health,” says Professor, Dr Renate Oberhoffer, the Chair and Professor of Preventive Paediatrics, at the Technical University of Munich in Germany.
“These new results are in line with our previous large-scale findings among British non-athlete youth, where moderate-to-vigorous physical activity was linked to slight increase in heart size,” says Andrew Agbaje, a physician and associate professor (docent) of clinical epidemiology and child health at the University of Eastern Finland and senior author of the study.
Agbaje adds: “Elite adult athletes have been shown to be at an increased risk of cardiac and vascular heart diseases as well as sudden cardiac death. While moderate-to-vigorous physical activity is advocated from youth for overall health, more attention needs to be paid to the adaptability of the cardiovascular system to strenuous exercise.”
The German study was financially supported by the Deutsche Stiftung für Herzforschung e.V., grant428
number F06/18.