Effects of a low-oxygen normal pressure environment on the respiratory, cardiovascular and metabolic responses to exercise

Abstract

[Purpose] We measured the respiratory, cardiovascular and metabolic responses to low intensity exercise in a low-oxygen normal pressure environment, and investigated its effect on energy metabolism. [Subjects] The subjects were 13 normally healthy males. [Method] The subjects performed exercise at a load of 70% of the anaerobic threshold on a bicycle ergometer under normal (20.9%) and low (14.5%) oxygen concentrations at a normal pressure of 1.0 atm. During exercise, we measured oxygen saturation, heart rate, and conducted respiratory gas analysis. [Results] Under the low oxygen condition, compared to the normal oxygen condition, the heart rate and respiratory minute volume during exercise showed significantly high values, while the lipid oxidation rate was significantly low. Conversely, the glucose oxidation rate was significantly high, and energy metabolism rose. [Conclusion] The results suggest that carbohydrate utilization is promoted by exercise under a low-oxygen normal pressure environment. © 2012, The Society of Physical Therapy Science. All rights reserved.