RESPIRATORY AND CIRCULATORY ADJUSTMENTS DURING PROLONGED EXERCISE IN ENDURANCE RUNNERS.
10.7600/jspfsm1949.32.293
- VernacularTitle:持久性走者の長時間運動時における呼吸循環応答特性
- Author:
KOHJI HIRAKOBA
;
KATSUMI ASANO
- Publication Type:Journal Article
- From:Japanese Journal of Physical Fitness and Sports Medicine
1983;32(5):293-301
- CountryJapan
- Language:Japanese
-
Abstract:
It was the purpose of this study to elucidate the difference between endurance runners and normal men in respiratory and circulatory adjustments during prolonged exercise, and to evaluate the relationship between the magnitude of the respiratory and circulatory“drift”and the endurance exercise capacity.
Ten male endurance runners (runner group), aged 19-23 years, and nine normal men (control group), aged 19-28 years, exercised on a bicycle ergometer for 60 min at a constant work load requiring 60% of Vo2max for each subject.
In the control group, VE increased approximately 20% from 10th to 60th min of prolonged exercise (P<0.05), with a corresponding decrease in PAco2 (P<0.05), whereas in the runner group VE and PAco2were remained constant throughout prolonged exercise. The above differences of VE and PAco2responses between the control and the runner group could not be accounted for by a rising body temperature and lactic acidosis, because it was found that the magnitude of the rise in rectal temperature (Tre) and the behavior in lactic acid (LA) were not different for the two groups. On the other hand, we failed to find the difference of the pattern in HR and SV responses to prolonged exercise in the runner group as compared with the control group. At each comparable time period during prolonged exercise, however, the percentage changes from the values at the 10th min in HR and SV were less in the runner group than in the control group. In addition, Vo2max (ml/kg/min) correlated significantly with the percentage changes in VE (r=-0.534, P<0.05), HR (r=-0.565, P<0.05), and SV (r=0.588, P<0.01) from 10th to 60th min of prolonged exercise.
The results of this study suggest that the endurance training may improve the magnitude of the respiratory and circulatory “drift”, which appears to become a limiting factor to endurance performance.
