Time delay in the mediation of ventilation (VE) by arterial CO2 pressure (PaCO2) was studied during recovery from short impulse-like exercises with different work loads of recovery. Subjects performed two tests including 10-s impulse like exercise with work load of 200 watts and 15-min recovery with 25 watts in test one and 50 watts in test two. V . E, end tidal CO2 pressure (PETCO2) and heart rate (HR) were measured continuously during rest, warming up, exercise and recovery. PaCO2 was estimated from PETCO2 and tidal volume (VT). Results showed that predicted arterial CO2 pressure (PaCO2 pre) increased during recovery in both tests. In both tests, VE increased and peaked at the end of exercise. VE decreased in the first few seconds of recovery but started to increase again. The highest correlation coefficient between PaCO2 pre and V . E was obtained in the time delay of 7 s (r=0.854) in test one and in time delays of 6 s (r=0.451) and 31 s (r=0.567) in test two. HR was significantly higher in test two than in test one. These results indicate that PaCO2 pre drives VE with a time delay and that higher work intensity induces a shorter time delay., R. Afroundeh, T. Arimitsu, R. Yamanaka, C. S. Lian, K. Shirakawa, T. Yunoki, T. Yano., and Obsahuje bibliografii
We investigated ventilation (V . E) control factors during recovery from light impulse-like exercise (100 watts) with a duration of 20 s. Blood ions and gases were measured at rest and during recovery. V . E, end tidal CO2 pressure (PETCO2) and respiratory exchange ratio (RER) were measured continuously during rest, exercise and recovery periods. Arterial CO2 pressure (PaCO2 pre) was estimated from PETCO2 and tidal volume (VT). RER at 20 s of exercise and until 50 s during recovery was significantly lower than RER at rest. Despite no change in arterialized blood pH level, PaCO2 pre was significantly higher in the last 10 s of exercise and until 70 s during recovery than the resting value. V . E increased during exercise and then decreased during recovery; however, it was elevated and was significantly higher than the resting value until 155 s (p<0.05). There was a significant relationship between V . E and PaCO2 pre during the first 70 s of recovery in each subject. The results suggest that PaCO2 drives V . E during the first 70 s of recovery after light impulse-like exercise. Elevated V . E in the interval from 70 s until 155 s during recovery might be due to neural factors., R. Afroundeh, ... [et al.]., and Obsahuje seznam literatury