Abstract

Objectives: This study was designed to investigate whether reduced breathing frequency during moderate intensity exercise produces similar metabolic responses as during exercise with spontaneous breathing at higher absolute intensity. Methods: Eight healthy male subjects performed a constant load test with reduced breathing frequency at 10 breaths per minute to exhaustion (B10) at the peak power output obtained during the incremental test with RBF (peak power output increased every two minutes for 30 W). The subjects then performed a constant load test with the spontaneous breathing to exhaustion (SB) at peak power output obtained during the incremental test with spontaneous breathing. Results: Respiratory parameters (VE, PETO2, PETCO2), metabolic parameters (VO2, VCO2) and oxygen saturation (SaO2) were measured during both constant load tests. Capillary blood samples were taken before and every minute during both constant load tests in order to measure lactate concentration ([LA-]) and parameters of capillary blood gases and acid base status (PO2, PCO2, pH). Regardless of the type of comparison (the data obtained at the defined time or maximum and minimum values during the exercise), there were significant differences between SB and B10 in all respiratory parameters, metabolic parameters and SaO2 (p ≤ 0.01 and 0.05). There were significantly lower [LA-] and PCO2 during B10, when compared to SB (p ≤ 0.01). However, there were no significant differences in pH during the exercise between different breathing conditions. Conclusion: It can be concluded that reduced breathing frequency during exercise at lower absolute intensity did not produce similar conditions as during the exercise with spontaneous breathing at higher absolute intensity. Verf.-Referat