Related Experiment Video
Updated: May 17, 2026

Supramaximal Intensity Hypoxic Exercise and Vascular Function Assessment in Mice
Published on: March 15, 2019
Intermittent normobaric hypoxic exposures at rest: effects on performance in normoxia and hypoxia
Igor B Mekjavic1, Tadej Debevec, Mojca Amon
1Department of Automation, Biocybernetics and Robotics, "Jozef Stefan" Institute, and Jozef Stefan International Postgraduate School, Ljubljana, Slovenia. igor.mekjavic@ijs.si
Introduction:
It has been speculated that short (-1-h) exposures to intermittent normobaric hypoxia at rest can enhance subsequent exercise performance. Thus, the present study investigated the effect of daily resting intermittent hypoxic exposures (IHE) on peak aerobic capacity and performance under both normoxic and hypoxic conditions.
Methods:
Eighteen subjects were equally assigned to either a control (CON) or IHE group and performed a 4-wk moderate intensity cycling exercise training (1 h x d(-1), 5 d x wk(-1)). The IHE group additionally performed IHE (60 min) prior to exercise training. IHE consisted of seven cycles alternating between breathing a hypoxic gas mixture (5 min; F1O2 = 0.12-0.09) and room air (3 min; F1O2 = 0.21). Normoxic and hypoxic peak aerobic capacity (VO2(peak)) and endurance performance were evaluated before (PRE), during (MID), upon completion (POST), and 10 d after (AFTER) the training period.
Results:
Similar improvements were observed in normoxic VO2(peak) tests in both groups [IHE: delta(POST-PRE) = +10%; CON: delta(POST-PRE) = + 14%], with no changes in the hypoxic condition. Both groups increased performance time in the normoxic constant power test only [IHE: delta(POST-PRE) = +108%; CON: delta(POST-PRE) = +114%], whereas only the IHE group retained this improvement in the AFTER test. Higher levels of minute ventilation were noted in the IHE compared to the CON group at the POST and AFTER tests.
Conclusion:
Based on the results of this study, the IHE does not seem to be beneficial for normoxic and hypoxic performance enhancement.
Related Concept Videos
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...
Acute Respiratory Failure-II
The underlying physiological abnormalities that contribute to hypoxemic respiratory failure include:
Physiological Control of Respiration
Breathing, a seemingly passive process, is regulated by the respiratory center in the brainstem. This center coordinates the involuntary control of respirations, which means it occurs without conscious effort, ensuring a smooth and uninterrupted pattern.
Regulation of Ventilation
The body maintains ventilation by monitoring levels of carbon dioxide (CO2), oxygen (O2), and hydrogen ion concentration (pH) in the arterial blood. Among these factors, the level of CO2 plays a crucial...
Hyperpnea and Hyperventilation
Alterations in Respiration II
In Biot's breathing, the respiratory rate and depth are irregular, alternating between periods of deep gasping and apnea. Common causes include...
Oxygen Transport in the Blood

