Investigate the effects of respiratory muscle fatigue and training on respiratory control, subjective perception and exercise performance.
Methods: Exercise tests with measurement of ventilation, gas exchange, chest wall motion, heart rate and different metabolites in arterial and venous blood. Measurement of respiratory muscle fatigue after exercise by measurement of twitch-transdiaphragmatic and gastric pressure during magnetic stimulation of phrenic of phrenic nerves and thoracic nerve roots respectively. Similarly, leg muscle fatigue is assessed objectively by measurement of quadriceps twitch force during femoral nerve stimulation.
Investigate muscle energy metabolism (glycogen, phosphocreatine, ATP, free phosphate) in humans.
Methods: 13C- and 31P-Magnetic Resonance Spectroscopy using a 4.7 Tesla Varian Spectrometer (collaboration with Drs R. Buchli and G. Kühne, PSI, Villigen).
Develop and refine exercise tests to assess aerobic performance in an easier way than the with the use of 'gold standard' methods.
Methods: Exercise tests on bicycle and treadmill ergometers with assessment of ventilation, gas exchange, heart rate and blood lactate concentration.
