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Hyperpnea training attenuates peripheral chemosensitivity and improves cycling endurance
Michael E McMahon1, Urs Boutellier, Richard M Smith
1Exercise Physiology, Swiss Federal Institute of Technology and University of Zurich, Switzerland.
The Journal of Experimental Biology
|November 15, 2002
Summary
Respiratory muscle training reduced peripheral chemoreceptor sensitivity in athletes. This training improved cycling performance, suggesting a minor role for chemoreceptors in exercise ventilation control.
Area of Science:
- Exercise Physiology
- Respiratory Physiology
- Cardiovascular Regulation
Background:
- Trained endurance athletes exhibit lower peripheral chemoreceptor (pR(c)) sensitivity and minute ventilation (E) during exercise than untrained individuals.
- This reduced pR(c) response may be linked to repeated high ventilation rates during endurance training.
Purpose of the Study:
- To investigate the effect of respiratory muscle training (RMT) on pR(c) sensitivity during exercise.
- To assess the impact of RMT on cycling performance in trained athletes.
Main Methods:
- 20 trained male cyclists were randomized into RMT or control groups.
- RMT involved 20 sessions of voluntary normocapnic hyperpnea to simulate high exercise ventilation.
- pR(c) sensitivity was measured using a modified Dejours O2 test during submaximal cycling; performance was assessed via a test to exhaustion.
Main Results:
- The RMT group showed significantly reduced pR(c) sensitivity compared to the control group.
- Cycling endurance time significantly improved in the RMT group versus the control group.
- Changes in pR(c) sensitivity did not correlate significantly with exercise ventilation or endurance time.
Conclusions:
- Simulated high ventilation via RMT reduces pR(c) sensitivity in trained cyclists.
- Despite reduced pR(c) sensitivity, RMT enhances cycling performance.
- The peripheral chemoreceptor's role in controlling ventilation during exercise appears to be minor.