TY - JOUR

T1 - Intensified training augments cardiac function, but not blood volume, in male youth elite ice hockey team players

AU - Fischer, Mads

AU - Jeppesen, Jan S.

AU - Vigh-Larsen, Jeppe F.

AU - Stöhr, Eric J.

AU - Mohr, Magni

AU - Wickham, Kate A.

AU - Gliemann, Lasse

AU - Bangsbo, Jens

AU - Hellsten, Ylva

AU - Hostrup, Morten

N1 - Publisher Copyright: © 2024 The Author(s). Experimental Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

PY - 2024

Y1 - 2024

N2 - While it is well-established that a period of interval training performed at near maximal effort, such as speed endurance training (SET), enhances intense exercise performance in well-trained individuals, less is known about its effect on cardiac morphology and function as well as blood volume. To investigate this, we subjected 12 Under-20 Danish national team ice hockey players (age 18 ± 1 years, mean ± SD) to 4 weeks of SET, consisting of 6–10 × 20 s skating bouts at maximal effort interspersed by 2 min of recovery conducted three times weekly. This was followed by 4 weeks of regular training (follow-up). We assessed resting cardiac function and dimensions using transthoracic echocardiography and quantified total blood volume with the carbon monoxide rebreathing technique at three time points: before SET, after SET and after the follow-up period. After SET, stroke volume had increased by 10 (2–18) mL (mean (95% CI)), left atrial end-diastolic volume by 10 (3–17) mL, and circumferential strain improved by 0.9%-points (1.7–0.1) (all P < 0.05). At follow-up, circumferential strain and left atrial end-diastolic volume were reverted to baseline levels, while stroke volume remained elevated. Blood volume and morphological parameters for the left ventricle, including mass and end-diastolic volume, did not change during the study. In conclusion, our findings demonstrate that a brief period of SET elicits beneficial central cardiac adaptations in elite ice hockey players independent of changes in blood volume.

AB - While it is well-established that a period of interval training performed at near maximal effort, such as speed endurance training (SET), enhances intense exercise performance in well-trained individuals, less is known about its effect on cardiac morphology and function as well as blood volume. To investigate this, we subjected 12 Under-20 Danish national team ice hockey players (age 18 ± 1 years, mean ± SD) to 4 weeks of SET, consisting of 6–10 × 20 s skating bouts at maximal effort interspersed by 2 min of recovery conducted three times weekly. This was followed by 4 weeks of regular training (follow-up). We assessed resting cardiac function and dimensions using transthoracic echocardiography and quantified total blood volume with the carbon monoxide rebreathing technique at three time points: before SET, after SET and after the follow-up period. After SET, stroke volume had increased by 10 (2–18) mL (mean (95% CI)), left atrial end-diastolic volume by 10 (3–17) mL, and circumferential strain improved by 0.9%-points (1.7–0.1) (all P < 0.05). At follow-up, circumferential strain and left atrial end-diastolic volume were reverted to baseline levels, while stroke volume remained elevated. Blood volume and morphological parameters for the left ventricle, including mass and end-diastolic volume, did not change during the study. In conclusion, our findings demonstrate that a brief period of SET elicits beneficial central cardiac adaptations in elite ice hockey players independent of changes in blood volume.

KW - blood volume

KW - echocardiography

KW - high-intensity interval training

KW - performance

U2 - 10.1113/EP091674

DO - 10.1113/EP091674

M3 - Journal article

C2 - 39014554

AN - SCOPUS:85198624116

JO - Experimental Physiology

JF - Experimental Physiology

SN - 0958-0670

ER -