Related Experiment Video
Updated: Mar 24, 2026

Supramaximal Intensity Hypoxic Exercise and Vascular Function Assessment in Mice
Published on: March 15, 2019
Effect of acute high-intensity exercise in normobaric hypoxia on Thoroughbred skeletal muscle
Kazuma Okabe1, Kazutaka Mukai2, Hajime Ohmura2
1Department of Biological Sciences, Graduate School of Medicine, Yamaguchi University, Yamaguchi, Japan.
Background:
We examined the effect of transient hypoxic exposure during high-intensity exercise on satellite cell activation and angiogenesis in Thoroughbred skeletal muscle.
Methods:
Six Thoroughbreds horses (6.3±0.8 years old) ran on a treadmill in normoxia (N; FIO2=21%) and hypoxia (H; FIO2=16%) at the same speed for the same duration, and oxygen consumption and plasma lactate and hemoglobin concentrations were measured. In addition, muscle biopsy samples were obtained from gluteus medius muscle before exercise and immediately, 4 hours, 24 hours, 3 days and 7 days after exercise, and immunohistochemical analysis and relative quantitative analysis of mRNA expression using real-time RT-PCR were performed.
Results:
Oxygen consumption during exercise in H was 29% lower than that in N, and plasma lactate concentration in H was 47% higher than that in N. The mRNA expressions of satellite cell activation-related factors slightly increased, but the mRNA expressions of factors related to angiogenesis and mitochondrial biogenesis slightly decreased. Fluorescence-stained basal lamina evaluation in stacked images 7 days after exercise showed no difference in capillary density between the two groups.
Conclusions:
These results suggest that transient hypoxic exposure during exercise increases the contribution of the glycolytic energy supply and promotes satellite cell activation, but does not facilitate angiogenesis and mitochondrial biogenesis.
Related Concept Videos
Exercise and Cardiovascular Response
Light to moderate physical activity initiates a series of interconnected responses in the body. The heart rate modestly increases in anticipation of the workout, followed by widespread vasodilation as oxygen consumption by skeletal muscles increases. This results in decreased peripheral resistance, increased capillary blood flow, and accelerated...
Exercise and Muscle Performance
Endurance exercises
Endurance exercises involve running, swimming, or cycling, which require repetitive movements with low force output. When a person engages in endurance exercise, a few noticeable changes occur in their skeletal muscles. For instance, the number of capillaries...
Muscle Recovery and Fatigue
Exercise and Cardiac Output
Sustained exercise increases the muscles' oxygen demand, which can be...
Hypoxia
Types of Hypoxia
There are four primary types of hypoxia, each resulting from a different cause:
1. Anemic hypoxia: This type occurs due to insufficient oxygen delivery caused by a lack of red blood cells (RBCs) or RBCs with abnormal or...
Oxygen Transport in the Blood

