Abstract
The purpose of this study was to evaluate the interactive effects of exercise duration
and intensity on the elevation of serum cardiac troponin T (cTnT) in trained adolescent
athletes following prolonged exercise in a laboratory-based setting. Thirteen male
adolescent runners (mean age 14.8±1.6 year) performed two 45-min and two 90-min constant-load
treadmill runs with intensities set at the running speeds that corresponded to either
80% or 100% ventilatory threshold (Thvent ): 80%Thvent 45 min, 80%Thvent 90 min, 100%Thvent 45 min and 100%Thvent 90 min. Serum cTnT was assessed pre and post exercise. In the 100%Thvent 45 min trial, the post-exercise serum cTnT level [(Median) 0.015 ng.ml−1 ; (Range)<0.01–0.375 ng.ml−1 ] was greater than that of the 80%Thvent 45 min (undetectable cTnT) and 80%Thvent 90 min (detectable cTnT in two subjects, 0.021 and 0.133 ng.ml−1 ) trials (P<0.01). The serum cTnT level was further increased in the 100%Thvent 90 min trial [(Median) 0.063 ng.ml−1 ; (Range)<0.01–0.417 ng.ml−1 ] when the treadmill run was sustained for an additional 45 min (P<0.05). Similar
changes were observed in the cTnT positive rate in subjects. These findings suggest
that exercise duration and intensity are essential factors in eliciting cTnT release
interactively following an endurance exercise. Nevertheless, exercise intensity compared
to duration appears to cause a more pronounced increase in cTnT levels.
Key words
cardiac marker - exercise - myocardium
References
The effects of strenuous exercise on cardiac markers in a sedentary population . University of Northern Colorado 2002
Correspondence
frankfu@hkbu.edu.hk
