Details

Autor(en) / Beteiligte

• Ørtenblad, Niels
• Zachariassen, Magnus
• Nielsen, Joachim
• Gejl, Kasper Degn

Titel

Substrate utilization and durability during prolonged intermittent exercise in elite road cyclists

Ist Teil von

• European journal of applied physiology, 2024-03

Ort / Verlag

Germany

Erscheinungsjahr

2024

Link zum Volltext

Quelle

SpringerLink

Beschreibungen/Notizen

• This study investigated the effects of prolonged intermittent cycling exercise on peak power output (PPO) and 6-min time-trial (6 min-TT) performance in elite and professional road cyclists. Moreover, the study aimed to determine whether changes in performance in the fatigued state could be predicted from substrate utilization during exercise and laboratory measures obtained in a fresh state. Twelve cyclists (age: 23 years [21;25]; body mass: 71.5 kg [66.7;76.8]; height: 181 cm [178;185]; O peak: 73.6 ml kg min [71.2;76.0]) completed a graded submaximal cycling test to determine lactate threshold (LT ), gross efficiency (GE), and maximal fat oxidation (MFO) as well as power output during a maximal 6 min-TT (MPO ) in a fresh condition. On a separate day, the cyclists completed a 4-h intermittent cycling protocol with a high CHO intake (100 g h ). Substrate utilization and PPO was measured hourly during the protocol, which was followed by another 6 min-TT. MPO and PPO was reduced by 10% [4;15] and 6% [0;6], respectively, after the cycling protocol. These reductions were accompanied by reductions in the anaerobic energy contribution and O peak, whereas the average O during the 6 min-TT was unchanged. Correlation analyses showed no strong associations between reductions in MPO and PPO and laboratory measures (i.e., LT , GE, MFO, O peak) obtained in the fresh condition. Additionally, fat oxidation rates during the cycling protocol were not related to changes in neither PPO nor MPO . PPO and MPO were reduced following prolonged intermittent cycling, but the magnitude of these reductions could not be predicted from laboratory measures obtained in the fresh condition.