Int J Sports Med 2022; 43(08): 708-714
DOI: 10.1055/a-1495-5612
Training & Testing

Muscle Oxygenation during Repeated Cycling Sprints in a Combined Hot and Hypoxic Condition

1   Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Japan
,
Nobukazu Kasai
2   Department of Sports Science, Japan Institute of Sports Sciences, Kita-ku, Japan
,
Nanako Hayashi
1   Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Japan
,
Haruka Yatsutani
1   Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Japan
,
3   School of Human Science (Exercise and Sport Sciences), The University of Western Australia, Perth, Australia
,
Kazushige Goto
1   Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Japan
› Institutsangaben

Funding We are grateful to all participants who conducted the experimental trials. This work was supported by Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (grant number: 17H02155).
Preview

Abstract

The aim of the present study was to examine the effects of a combined hot and hypoxic environment on muscle oxygenation and performance during repeated cycling sprints. In a single-blind, counterbalanced, cross-over research design, 10 male athletes performed three sets of 3 × 10-s maximal pedaling interspersed with 40-s recovery between sprints under four different environments. Each condition consisted of a control (CON; 20°C, 20.9% FiO2), normobaric hypoxia (HYP; 20°C, 14.5% FiO2), hot (HOT; 35°C, 20.9% FiO2), and combined hot and normobaric hypoxia (HH; 35°C, 14.5% FiO2). Power output and vastus lateralis muscle oxygenation were measured. Peak power output was significantly higher in HOT (892±27 W) and HH (887±24 W) than in CON (866±25 W) and HYP (859±25 W) during the first set (p<0.05). The increase in total hemoglobin during recovery periods was larger in HH than in HYP (p<0.05), while change in tissue saturation index was smaller in HYP than in CON and HOT (p<0.05). The findings suggest that the combination of hot and hypoxia during repeated cycling sprints presented different characteristics for muscle metabolism and power output compared to temperature or altitude stressor alone.



Publikationsverlauf

Eingereicht: 28. Januar 2021

Angenommen: 19. April 2021

Artikel online veröffentlicht:
27. Januar 2022

© 2022. Thieme. All rights reserved.

Georg Thieme Verlag
Rüdigerstraße 14, 70469 Stuttgart, Germany