Post marathon cardiac troponin T is associated with relative exercise intensity

Abstract Objectives This study aimed to investigate whether measures of cardiopulmonary fitness and relative exercise intensity were associated with high sensitivity cardiac troponin T (cTnT) rise after a road marathon. Methods Fifty-two marathon runners (age 39 ± 11 years, body mass 76.2 ± 12.9 kg, height 1.74 ± 0.09 m) attended the laboratory between 2 and 3 weeks prior to attempting the Brighton Marathon, UK. Running economy at 10 km h −1 (RE10) and race pace (RERP), ventilatory threshold (VT) and VO 2 max tests were completed. CTnT was measured within 48 h prior to the marathon and within 10 min of completing the marathon, using a high sensitivity assay. Heart rates (HR) were recorded throughout the marathon. Results Runners demonstrated a significant increase in cTnT over the marathon (pre-race 5.60 ± 3.27 ng L −1 , post-race 74.52 ± 30.39 ng L −1 , p   0.001). Markers of endurance performance such as running economy (10 km h −1 223 ± 18 ml kg −1  km −1 ; race pace 225 ± 22 ml kg −1  km −1 ), VT (38.5 ± 6.4 ml kg −1  min −1 ) and V ˙ O 2 max (50.9 ± 7.7 ml kg −1  min −1 ) were not associated with post-race cTnT. Runners exercise intensity correlated with post-race cTnT (mean HR %VT 104 ± 5%, r  = 0.50; peak HR %VT 118 ± 8%, r  = 0.68; peak HR % V ˙ O 2 max 96 ± 6, r  = 0.60, p  p  Conclusions CTnT increases above reference limits during a marathon. Magnitude of cTnT rise is related to exercise intensity relative to ventilatory threshold and V ˙ O 2 max, but not individuals’ absolute cardiopulmonary fitness, training state or running history.