Cardiac troponin (cTn) is a key protein involved in the regulation of muscular contraction in cardiac muscle, through interaction with actin, tropomyosin, and calcium ions during the sliding filament mechanism. This study evaluated the effect of endurance exercise (marathon running) on cTn release in 151 athletes using serological data. Figure A shows the time course of exercise-induced cTn concentration changes. Figure B displays individual post-marathon cTnI levels relative to the upper reference limit (URL) for normal.
https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.121.056208
(a) Refer to Figure A. At what time interval is peak cTn concentration observed post-exercise?
(b) Refer to Figure B. the percentage of individuals who had post-marathon cTn concentrations above the normal URL.
