TY - JOUR
T1 - Effects of Matched Intermittent and Continuous Exercise on Changes of Cardiac Biomarkers in Endurance Runners
AU - Li, Feifei
AU - Nie, Jinlei
AU - Zhang, Haifeng
AU - Fu, Frank
AU - Yi, Longyan
AU - Hopkins, Will
AU - Liu, Yang
AU - Lu, Yifan
N1 - Publisher Copyright:
© Copyright © 2020 Li, Nie, Zhang, Fu, Yi, Hopkins, Liu and Lu.
PY - 2020/1/31
Y1 - 2020/1/31
N2 - Purpose: Endurance runners training with high-intensity intermittent exercise might experience damage to cardiac muscle. We have therefore compared changes of cardiac biomarkers after workload-matched intermittent and continuous exercise. Methods: Twelve endurance runners [11 males, 1 female; means ± SD (Formula presented.) O2max, 62.4 ± 5.4 ml kg–1 min–1; velocity of (Formula presented.) O2max (v (Formula presented.) O2max), 17.1 ± 1.4 km h–1] completed an intermittent and continuous exercise trial in random order. Intermittent exercise consisted of running at 90% v (Formula presented.) O2max for 2 min followed by 50% v (Formula presented.) O2max for 2 min, repeated for 92 min. Continuous exercise was performed at 70% v (Formula presented.) O2max for 92 min. Blood samples were drawn before and 0, 2, 4, 24, and 48 h after exercise for assay of various cardiac biomarkers. Changes in concentration of biomarkers were averaged for the comparison of intermittent with continuous exercise after adjustment for baseline concentration and exercise intensity expressed as percent of heart-rate reserve (%HRR); magnitudes were assessed by standardization. Results: There were moderate and large increases in high-sensitivity cardiac troponin-I and -T respectively following exercise. The differences between the increases adjusted to the mean intensity of 78 %HRR were trivial, but at 85 %HRR the increases for cardiac troponin-I and -T were moderately higher for intermittent compared with continuous exercise (factor difference, ×/÷90% confidence limits: 3.4, ×/÷1.9 and 2.1, ×/÷1.8 respectively). Differences in the changes in other cardiac biomarkers were trivial. Conclusion: Prolonged intermittent exercise is potentially more damaging to cardiac muscle than continuous exercise of the same average running speed at higher average heart rates in endurance runners.
AB - Purpose: Endurance runners training with high-intensity intermittent exercise might experience damage to cardiac muscle. We have therefore compared changes of cardiac biomarkers after workload-matched intermittent and continuous exercise. Methods: Twelve endurance runners [11 males, 1 female; means ± SD (Formula presented.) O2max, 62.4 ± 5.4 ml kg–1 min–1; velocity of (Formula presented.) O2max (v (Formula presented.) O2max), 17.1 ± 1.4 km h–1] completed an intermittent and continuous exercise trial in random order. Intermittent exercise consisted of running at 90% v (Formula presented.) O2max for 2 min followed by 50% v (Formula presented.) O2max for 2 min, repeated for 92 min. Continuous exercise was performed at 70% v (Formula presented.) O2max for 92 min. Blood samples were drawn before and 0, 2, 4, 24, and 48 h after exercise for assay of various cardiac biomarkers. Changes in concentration of biomarkers were averaged for the comparison of intermittent with continuous exercise after adjustment for baseline concentration and exercise intensity expressed as percent of heart-rate reserve (%HRR); magnitudes were assessed by standardization. Results: There were moderate and large increases in high-sensitivity cardiac troponin-I and -T respectively following exercise. The differences between the increases adjusted to the mean intensity of 78 %HRR were trivial, but at 85 %HRR the increases for cardiac troponin-I and -T were moderately higher for intermittent compared with continuous exercise (factor difference, ×/÷90% confidence limits: 3.4, ×/÷1.9 and 2.1, ×/÷1.8 respectively). Differences in the changes in other cardiac biomarkers were trivial. Conclusion: Prolonged intermittent exercise is potentially more damaging to cardiac muscle than continuous exercise of the same average running speed at higher average heart rates in endurance runners.
KW - biomarkers
KW - cardiac troponin
KW - high-intensity intermittent exercise
KW - intensity
KW - marathon runners
UR - http://www.scopus.com/inward/record.url?scp=85079504817&partnerID=8YFLogxK
U2 - 10.3389/fphys.2020.00030
DO - 10.3389/fphys.2020.00030
M3 - Article
AN - SCOPUS:85079504817
SN - 1664-042X
VL - 11
JO - Frontiers in Physiology
JF - Frontiers in Physiology
M1 - 30
ER -