Post marathon cardiac troponin T is associated with relative exercise intensity.

<bold>Objectives: </bold>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.<bold>Methods: </bold>Fifty-two marathon runners (age 39±11 years, body mass 76.2±12.9kg, height 1.74±0.09m) attended the laboratory between 2 and 3 weeks prior to attempting the Brighton Marathon, UK. Running economy at 10kmh-1 (RE10) and race pace (RERP), ventilatory threshold (VT) and VO2max tests were completed. CTnT was measured within 48h prior to the marathon and within 10min of completing the marathon, using a high sensitivity assay. Heart rates (HR) were recorded throughout the marathon.<bold>Results: </bold>Runners demonstrated a significant increase in cTnT over the marathon (pre-race 5.60±3.27ngL-1, post-race 74.52±30.39ngL-1, p<0.001). Markers of endurance performance such as running economy (10kmh-1 223±18mlkg-1km-1; race pace 225±22mlkg-1km-1), VT (38.5±6.4mlkg-1min-1) and V˙O2max (50.9±7.7mlkg-1min-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˙O2max 96±6, r=0.60, p<0.05) and was different between the low, medium and high cTnT groups (p<0.05).<bold>Conclusions: </bold>CTnT increases above reference limits during a marathon. Magnitude of cTnT rise is related to exercise intensity relative to ventilatory threshold and V˙O2max, but not individuals' absolute cardiopulmonary fitness, training state or running history. [ABSTRACT FROM AUTHOR]