Observational Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Cardiol. Jan 26, 2020; 12(1): 35-43
Published online Jan 26, 2020. doi: 10.4330/wjc.v12.i1.35
Impact of training specificity on exercise-induced cardiac troponin elevation in professional athletes: A pilot study
Johan O Wedin, Nicolena S Nyberg, Anders E Henriksson
Johan O Wedin, Department of Clinical Physiology, Sundsvall County Hospital, Sundsvall 851 86, Sweden
Johan O Wedin, Nicolena S Nyberg, Anders E Henriksson, Department of Clinical Chemistry, Sundsvall County Hospital, Sundsvall 851 86, Sweden
Anders E Henriksson, Department of Natural Sciences, Mid Sweden University, Sundsvall 851 70, Sweden
Author contributions: Wedin JO and Henriksson AE were equally involved in designing the study, collecting and analyzing the data, and preparing the manuscript; Wedin JO, Nyberg NS, and Henriksson AE reviewed and revised the final version of the manuscript.
Institutional review board statement: Please see the uploaded files where you can find the approved Institutional Review Board Statement.
Informed consent statement: Please see the uploaded files where we attached the informed consent forms for all participants.
Conflict-of-interest statement: The authors report no relevant conflicts of interest.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Anders E Henriksson, MD, PhD, Professor, Department of Clinical Chemistry, Sundsvall County Hospital, Sundsvall 851 86, Sweden. anders.henriksson@rvn.se
Received: May 31, 2019
Peer-review started: June 4, 2019
First decision: August 2, 2019
Revised: September 20, 2019
Accepted: October 14, 2019
Article in press: October 15, 2019
Published online: January 26, 2020
Processing time: 208 Days and 19.3 Hours
Abstract
BACKGROUND

Release of cardiac biomarkers is common after strenuous endurance exercise, but data on intermittent exercise are scarce. It has not been investigated whether cardiac troponin elevation is influenced depending on the type of exercise that an athlete is adapted to perform. We hypothesized that intermittent but not continuous exercise induces cardiac troponin elevation in professional athletes adapted to high-intensity intermittent exercise.

AIM

To examine how training specificity impacts high-sensitivity cardiac troponin T (hs-cTnT) release.

METHODS

Nine professional floorball players participated in the study, which comprised two different exercise tests: a continuous incremental cycle ergometer test and a Yo-Yo Intermittent Recovery 2 (Yo-Yo IR2) test. Serial assessment of hs-cTnT was performed after the cycle ergometer test and the Yo-Yo IR2 test (baseline, 0, 2, 6, and 24 h).

RESULTS

No hs-cTnT elevation above the myocardial damage cutoff (≥ 14 ng/L) was shown after the cycle ergometer test, whereas hs-cTnT levels rose over the cutoff in three of nine participants after the Yo-Yo IR2 test. The hs-cTnT levels peaked at 6 h after both tests, but were significantly higher after the Yo-Yo IR2 test compared to the cycle ergometer test (median hs-cTnT concentration 10.6 ng/L vs 7.8 ng/L, P = 0.038). All levels returned to baseline within 24 h.

CONCLUSION

In professional athletes adapted to high-intensity intermittent exercise, hs-cTnT was significantly elevated after intermittent but not continuous exercise. This principle of specificity training should be considered when designing future studies to avoid misinterpretation of hs-cTnT elevation.

Keywords: Athlete; Exercise; Floorball; Sports medicine; Yo-Yo IR2 test; Myocardial injury; Cardiac troponin

Core tip: Exercise-induced cardiac troponin elevation is common after continuous exercise, but the response to intermittent exercise is less investigated. Nine professional athletes adapted to intermittent exercise underwent serial assessment of high-sensitivity cardiac troponin T (hs-cTnT) after continuous exercise and intermittent exercise tests. The intermittent exercise test induced higher levels of hs-cTnT compared to the continuous exercise test. The peak hs-cTnT concentration was observed 6 h after the exercise tests. The principle of specificity training and timing of blood sampling should be considered when designing future studies to avoid misinterpretation of hs-cTnT elevation.