Abstract
Introduction
In triathlon, the running component has the largest impact on the final ranking in a race and depends mainly on maximal oxygen uptake and oxygen (Cox) or energy cost of running (Cen) (Millet & Bentley, 2004). Since running always follows swimming and cycling, fatigue accumulated from prior exercise could negatively impact Cox/Cen and thus performance, which has been shown in adult middle-level as opposed to elite triathletes (Millet et al., 2000). However, as little evidence is available on the influence of prior exercise on Cox/Cen in youth athletes, this study examined Cox/Cen, substrate utilization, and kinematic parameters in young triathletes before and after strenuous cycling.
Methods
17 youth squad triathletes (16 ± 1 yrs; 58.1 ± 6.9 mL·min-1·kg-1) completed a combined running and cycling incremental protocol. Starting with three 5-min steps on a treadmill (2.8 m·s-1 + 0.4 m·s-1, 30 s rest), athletes subsequently performed a 3-min incremental cycling test to exhaustion (~1.5 W·kg-1 + 20 W), followed by a 5-min incremental test to exhaustion on the treadmill with an 8-min passive rest in between. Cox/Cen, carbohydrate (CHO) and fat oxidation (FO) were estimated from spirometry and stride length, frequency, and ground contact times using a light barrier system. These values were compared between the three running stages under fresh (before) and prefatigued (after cycling) conditions by rmANOVA.
Results
Neither Cox (211 ± 16 and 211 ± 18 mL·kg-1·km-1, p = 0.78), Cen (4.6 ± 0.3 and 4.5 ± 0.4 kJ·kg-1·km-1, p = 0.06), nor stride length (1.17 ± 0.14 and 1.18 ± 0.20 m, p = 0.58), frequency (2.72 ± 0.14 and 2.72 ± 0.15 Hz, p = 0.65), and contact time (0.30 ± 0.04 and 0.30 ± 0.04 s, p = 0.24) changed significantly from fresh to prefatigued running. However, CHO (2.85 ± 0.63 and 2.09 ± 0.69 g·min-1, p < 0.001) significantly decreased, while FO (0.11 ± 0.13 and 0.41 ± 0.23 g·min-1, p < 0.001) significantly increased.
Discussion
Strenuous cycling did not affect Cox, Cen, and running kinematics in youth squad triathletes. However, since athletes relied more on fat oxidation during running in prefatigued compared to fresh conditions, implementation of training strategies to improve fat metabolism in youth triathletes may be suggested.
Literature
Millet, G. P., & Bentley, D. J. (2004) The physiological responses to running after cycling in elite junior and senior triathletes. Int J Sports Med, 25(3), 191–197.
Millet, G. P. et al. (2000). Alterations in running economy and mechanics after maximal cycling in triathletes: influence of performance level. Int J Sports Med, 21(2), 127–132.
In triathlon, the running component has the largest impact on the final ranking in a race and depends mainly on maximal oxygen uptake and oxygen (Cox) or energy cost of running (Cen) (Millet & Bentley, 2004). Since running always follows swimming and cycling, fatigue accumulated from prior exercise could negatively impact Cox/Cen and thus performance, which has been shown in adult middle-level as opposed to elite triathletes (Millet et al., 2000). However, as little evidence is available on the influence of prior exercise on Cox/Cen in youth athletes, this study examined Cox/Cen, substrate utilization, and kinematic parameters in young triathletes before and after strenuous cycling.
Methods
17 youth squad triathletes (16 ± 1 yrs; 58.1 ± 6.9 mL·min-1·kg-1) completed a combined running and cycling incremental protocol. Starting with three 5-min steps on a treadmill (2.8 m·s-1 + 0.4 m·s-1, 30 s rest), athletes subsequently performed a 3-min incremental cycling test to exhaustion (~1.5 W·kg-1 + 20 W), followed by a 5-min incremental test to exhaustion on the treadmill with an 8-min passive rest in between. Cox/Cen, carbohydrate (CHO) and fat oxidation (FO) were estimated from spirometry and stride length, frequency, and ground contact times using a light barrier system. These values were compared between the three running stages under fresh (before) and prefatigued (after cycling) conditions by rmANOVA.
Results
Neither Cox (211 ± 16 and 211 ± 18 mL·kg-1·km-1, p = 0.78), Cen (4.6 ± 0.3 and 4.5 ± 0.4 kJ·kg-1·km-1, p = 0.06), nor stride length (1.17 ± 0.14 and 1.18 ± 0.20 m, p = 0.58), frequency (2.72 ± 0.14 and 2.72 ± 0.15 Hz, p = 0.65), and contact time (0.30 ± 0.04 and 0.30 ± 0.04 s, p = 0.24) changed significantly from fresh to prefatigued running. However, CHO (2.85 ± 0.63 and 2.09 ± 0.69 g·min-1, p < 0.001) significantly decreased, while FO (0.11 ± 0.13 and 0.41 ± 0.23 g·min-1, p < 0.001) significantly increased.
Discussion
Strenuous cycling did not affect Cox, Cen, and running kinematics in youth squad triathletes. However, since athletes relied more on fat oxidation during running in prefatigued compared to fresh conditions, implementation of training strategies to improve fat metabolism in youth triathletes may be suggested.
Literature
Millet, G. P., & Bentley, D. J. (2004) The physiological responses to running after cycling in elite junior and senior triathletes. Int J Sports Med, 25(3), 191–197.
Millet, G. P. et al. (2000). Alterations in running economy and mechanics after maximal cycling in triathletes: influence of performance level. Int J Sports Med, 21(2), 127–132.
Titel in Übersetzung | Intensives Radfahren hat keinen Einfluss auf die Laufökonomie und Kinematik von Nachwuchs-Kader Triathlet*innen |
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Originalsprache | Englisch |
Titel | Leistung steuern. Gesundheit stärken. Entwicklung fördern : 26. dvs-Hochschultag, Bochum, 20.–22. September 2023 : Abstracts |
Herausgeber*innen | Torsten Schlesinger, Elke Grimminger-Seidensticker, Alexander Ferrauti, Michael Kellmann, Christian Thiel, Lisa Kullik |
Seitenumfang | 1 |
Band | 301 |
Erscheinungsort | Hamburg |
Herausgeber (Verlag) | Feldhaus, Edition Czwalina |
Erscheinungsdatum | 2023 |
Seiten | 295 |
ISBN (Print) | 9783880207134 |
Publikationsstatus | Veröffentlicht - 2023 |
Veranstaltung | Sportwissenschaftlticher Hochschultag der Deutschen Vereinigung für Sportwissenschaft (dvs): Leistung steuern. Gesundheit stärken. Entwicklung fördern. - Bochum Dauer: 20.09.2023 → 22.09.2023 Konferenznummer: 26 |