Related Experiment Videos
Exercise-dependent ventilatory sensitivity to hypoxia in Andean natives
Robert F Grover1, Julio C Cruz, Estelle B Grover
1Department of Medicine, University of Colorado School of Medicine, Denver, CO, USA. drgrover@charter.net
Respiratory Physiology & Neurobiology
|October 19, 2002
Summary
Andean natives (NAT) show a blunted resting ventilatory response to hypoxia. However, during exercise, their hypoxic sensitivity emerges, increasing with intensity, though less than acclimatized sojourners (SOJ).
Area of Science:
- Physiology
- Altitude Medicine
- Respiratory Physiology
Background:
- Andean natives (NAT) exhibit a blunted ventilatory response to hypoxia at rest.
- The interaction between hypoxia and exercise in NAT remains understudied.
Purpose of the Study:
- To investigate the ventilatory response to hypoxia during graded submaximal exercise in Andean natives.
- To compare this response with that of sojourners acclimatized to high altitude.
Main Methods:
- 13 Andean natives (NAT) and 6 sojourners (SOJ) performed three levels of submaximal exercise.
- Ventilation was measured breathing either oxygen (PI(O2) 410 Torr) or ambient air (PI(O2) 86 Torr).
Main Results:
- Soourners (SOJ) showed increased ventilation with hypoxia at all exercise intensities.
- Andean natives (NAT) demonstrated a delayed onset of hypoxic ventilatory sensitivity, but it increased with exercise intensity.
- Hypoxia increased ventilation by 18% in NAT versus 30% in SOJ at the highest workload.
Conclusions:
- Andean natives (NAT) do exhibit exercise-induced ventilatory sensitivity to hypoxia.
- This sensitivity is intensity-dependent and emerges above a certain exercise threshold.
- The magnitude of hypoxic ventilatory response during exercise in NAT is less than in acclimatized sojourners (SOJ).