For a further depiction of exercise-induced cardiac dysfunction, N-terminal 
pro-brain natriuretic peptide (NT-pro-BNP) and cardiac troponin T (cTnT) were 
measured in recreational cyclists (n = 29) during the Otztal Radmarathon 2004. 
In all subjects, NT-pro-BNP significantly increased from 28 +/- 21 to 278 +/- 
152 ng/L immediately after the race (p <0.001), decreased again on the following 
day, and returned to baseline values 1 week later. The mean percentage increase 
in NT-pro-BNP was 1,128 +/- 803%. CTnT, negative in all subjects before the 
race, increased transiently in 13 athletes (45%), with levels ranging from 0.043 
to 0.224 mug/L in 8 of them (28%). One day after competition, cTnT had 
normalized in all athletes. Because of the typical release of kinetics, the 
deflection of NT-pro-BNP is considered to be the adequate volume regulatory 
response of a hemodynamically stressed heart to prolonged strenuous exercise. 
The observed kinetics of cTnT substantiate a release from the free cytoplasmatic 
pool due to the half-life of cytosolic cTnT. In healthy cyclists, transient 
increases in NT-pro-BNP and cTnT are more likely to reflect cardiac fatigue than 
injury.