Abstract Introduction Examination of specific cardiac enzymes and peptide fragments is essential in cases of acute myocardial ischemia and heart failure. According to previous data, exhausting physical effort may cause temporary increase of cardiac necroenzyme levels, while no information is available on their resting values in athletes. Methods Resting serum levels of hsTroponinT, CKMB, LDH and NT-proBNP were measured as part of extended sports cardiology screening in healthy athletes and a healthy sedentary non-athlete control group. Depending on normality, groups were compared with two-tailed Student's t-test or Mann-Whitney U-test. Statistical analysis was processed in RStudio integrated development environment. Results Results of 237 healthy athletes from different sports (male: 144, age: 19.1±5.9 years, training: 16.0±6.7 hours/week) and 53 sedentary non-athletes (male: 23, age: 19.8±3.2 years, training: 2.6±2.3 hours/week) were analysed. In athletes, increased resting cardiac marker levels were measured as follows: CKMB: 6.3% (n=15), LDH: 3.4% (n=8), hsTroponinT: 4.2% (n=10), NT-proBNP: 0.8% (n=2) of the cases. No elevation of CKMB and hsTroponin T levels were measured in the control group, while only single cases of increased LDH and NT-proBNP were detected. We measured higher levels of CKMB (17.6±7.3 vs. 12.3±3.4 U/l, p<0.001), LDH (322.4±60.8 vs. 286.0±51.1 U/l, p<0.001) and hsTroponinT (6.2±4.7 vs. 4.3±1.4 ng/l, p<0.05), while lower levels of NT-proBNP (23.9±27.2 vs. 49.8±38.7 pg/ml, p<0.001) in athletes compared to the control group. In male athletes, higher levels of CKMB (18.5±6.6 vs. 16.0±8.2 U/l, p<0.001), LDH (337.0±62.2 vs. 300.7±51.9 U/l, p<0.001) and hsTroponinT (7.0±5.3 vs. 4.3±1.9 ng/l, p<0.001), and lower levels of NT-proBNP (19.8±23.1 vs. 35.0±34.1 pg/ml, p<0.001) were measured compared to female athletes. Levels of hsTroponinT decreased in athletes due to increasing age (r=−0.20, p<0.05). Discussion According to our results, resting levels of cardiac markers show significant alterations due to sport adaptation of the heart. These changes depend on age and sex as well. Conclusions Our research attract attention to different assessment of cardiac markers in athletes in respect of recognition of cardiovascular pathologies. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): This project was supported by a grant from the National Research, Development and Innovation Office (NKFIH) of Hungary.