News Release

Gender differences in respiratory response to exercise and hypoxia

Peer-Reviewed Publication

American Physiological Society

PITTSBURGH – Pa. -- Neural and chemical mechanisms interact in adjusting breathing pattern and ventilation during exercise. Dr. Magdalena Seebauer of the Institute of Physiology, University of Zurich, Switzerland, investigated gender differences in these interactions by analyzing phase coordination of breathing and exercise rhythms during bicycling in normoxia and hypoxia corresponding to 4000m altitude.

Dr. Seebauer will discuss the findings during the upcoming conference, Genomes and Hormones: An Integrative Approach to Gender Differences in Physiology, being sponsored by the American Physiological Society (APS), and held October 17-20, 2001, at the Westin Convention Center, Pittsburgh, Pa.

Methodology
Dr. Seebauer and her colleagues examined 22 men and 22 women (19-41 years) who underwent exercise tests of six minutes at workloads of 50, 80 and 110 percent of their anaerobic threshold (AT). Continuous breath-by-breath recordings of several respiratory parameters, oxygen saturation and leg movement were carried out. Ventilatory response to hypoxia (HVR) was determined by a four minute exposure to isocapnic hypoxia.

Results
In normoxia, men coordinated distinctively more at 110 percent AT than at 50 percent AT, whereas in women, coordination remained nearly constant. At 110 percent AT men reduced the degree of coordination from normoxia to hypoxia, whereas in women, coordination increased. HVR tended to be lower in women than in men.

Conclusions
The investigators concluded that in men, the degree of coordination depends on workload level and on hypoxia, whereas in women, coordination remains stable regardless of experimental condition. The higher chemosensitivity in men may account for the reduction of coordination in hypoxia. <

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The American Physiological Society (APS) was founded in 1887 to foster basic and applied science, much of it relating to human health. The Bethesda, MD-based Society has more than 10,000 members and publishes 3,800 articles in its 14 peer-reviewed journals every year.

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Contact: Donna Krupa:
703.527.7357
Cell: 703.967.2751 or
djkrupa1@aol.com

Or at The APS Newsroom @
The Westin Convention Center
Pittsburgh, PA
October 17-20, 2001
Tel: 412.281.3700 (The Crawford Room)


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