The aim of this study was to compare the changes in the content of cTnI, cTnT and some biochemical parameters (CK–MB, LDH, AST, ALT) in Arabian racehorses before and after training. Diagnosis of myocardial disease in horses is very difficult due to the lack of specific cardiac signs. Cardiac diseases are seen as a cause of sudden death or decreased performance in horses. It has also been reported that excessive exercise may cause transient myocardial damage. In our study, 20 healthy stallion Arabian racehorses aged 4–10 y (6.00 ± 0.52 y) were used. Five millilitres of blood was collected from the V. jugularis of clinically healthy horses into serum tubes before and after training. Training time was determined as 30 min for each horse. Pre-training cTnI, cTnT, CK–MB, LDH, AST, and ALT contents were determined to be 0.130 ± 0.01 ng/mL, 0.007 ± 0.00 ng/mL, 231.15 ± 8.96 U/L, 692.45 ± 34.12 U/L, 309.92 ± 18.48 U/L, and 11.83 ± 0.92 U/L, respectively. After training, cTnI, cTnT, CK–MB, LDH, AST, and ALT contents were determined to be 0.169 ± 0.01 ng/mL, 0.008 ± 0.00 ng/mL, 289.80 ± 10.96 U/L, 704.25 ± 22.03 U/L, 328.47 ± 19.58 U/L, and 15.24 ± 1.03 U/L, respectively. As a result, it was determined that exercise triggered myocardial damage to some extent in Arabian horses. Exercise stimulates troponin release and the differences that may occur in troponin tests in horses after exercise should be taken into consideration.