*Article* **Cardiopulmonary Exercise Testing and Cardiac Biomarker Measurements in Young Football Players: A Pilot Study**

**Alexandru-Dan Costache 1,2,†, Mihai Roca 1,2,\*, Cezar Honceriu 3,†, Irina-Iuliana Costache 1,4,†, Maria-Magdalena Leon-Constantin 1,2, Ovidiu Mitu 1,4,†, Radu-S, tefan Miftode 1,4,†, Alexandra Mas,taleru 1,2,†, Dan Iliescu-Halit,chi 1,5, Codrut,a-Olimpiada Halit,chi-Iliescu 6,7, Adriana Ion 1,4, S, tefania-Teodora Duca 1,4, Delia-Melania Popa 1, Beatrice Abălasei 3, Veronica Mocanu <sup>8</sup> and Florin Mitu 1,2**


**Abstract:** Constant and intense physical activity causes physiological adaptive changes in the human body, but it can also become a trigger for adverse events, such as sudden cardiac arrest or sudden cardiac death. Our main objective was to assess the use of combined cardiopulmonary exercise testing (CPET) and cardiac biomarker determinants in young professional athletes. We conducted a study which involved the full examination of 19 football players, all male, aged between 18 and 20 years old. They underwent standard clinical and paraclinical evaluation, a 12-lead electrocardiogram (ECG), and transthoracic echocardiography (TTE). Afterwards, a tailored CPET was performed and peripheral venous blood samples were taken before and 3 h after the test in order to determine five biomarker levels at rest and post-effort. The measured biomarkers were cardiac troponin I (cTnI), myoglobin (Myo), the MB isoenzyme of creatine-kinase (CK-MB), the N-terminal prohormone of brain natriuretic peptide (NT-proBNP) and D-dimers. While cTnI and NT-proBNP levels were undetectable both at rest and post-effort in all subjects, the variations in Myo, CK-MB and D-dimers showed significant correlations with CPET parameters. This highlights the potential use of combined CPET and biomarker determinants to evaluate professional athletes, and encourages further research on larger study groups.

**Keywords:** athletes; cardiopulmonary exercise testing; cardiac biomarkers
