BackgroundRegular exercise training is an important factor in prevention of myocardial infarction (MI). However, little is known whether exercise engagement prior to MI is related to the magnitude of post-MI cardiac biomarker concentrations and clinical outcomes.ObjectivesWe tested the hypothesis that exercise engagement in the week prior MI is related to lower cardiac biomarker concentrations following ST-elevated MI (STEMI).MethodsWe recruited hospitalised STEMI patients and assessed the amount of exercise engagement in the 7 days preceding MI onset using a validated questionnaire. Patients were classified as ‘exercise’ if they performed any vigorous exercise in the week prior MI, or as ‘control’ if they did not. Post-MI peak concentrations of high-sensitive cardiac troponin T (peak-hs-cTnT) and creatine kinase (peak-CK) were examined. We also explored whether exercise engagement prior MI is related to the clinical course (duration of hospitalisation and incidence of in-hospital, 30-day and 6-month major adverse cardiac events (reinfarction, target vessel revascularisation, cardiogenic shock or death)).ResultsIn total, 98 STEMI patients were included, of which 16% (n=16) was classified as ‘exercise’, and 84% (n=82) as ‘control’. Post-MI peak-hs-cTnT and peak-CK concentrations were lower in the exercise group (941 (645–2925) ng/mL; 477 (346–1402) U/L, respectively) compared with controls (3136 (1553–4969) ng/mL, p=0.010; 1055 (596–2019) U/L, p=0.016, respectively). During follow-up, no significant differences were found between both groups.ConclusionEngagement in exercise is associated with lower cardiac biomarker peak concentrations following STEMI. These data could provide further support for the cardiovascular health benefits of exercise training.