Circadian rhythms in gas exchange kinetics at the onset of moderate bicycle exercise.
- VernacularTitle:中強度自転車運動初期におけるガス交換動態の日内変動
- Author:
TOMOYUKI SHIOJIRI
;
TAKATSUGU SHIMANA
;
SHUNSAKU KOGA
;
NARIHIKO KONDO
;
ATSUSHI IWATA
- Publication Type:Journal Article
- Keywords:
Circadian rhythm;
Rectal temperature;
Oxygen uptake kinetics
- From:Japanese Journal of Physical Fitness and Sports Medicine
1993;42(5):455-460
- CountryJapan
- Language:Japanese
-
Abstract:
Circadian rhythms (diurnal variations) in many physiological parameters have been reported. However, there are no data on gas exchange kinetics at the onset of exercise. The purpose of this study was to establish whether there are circadian rhythms in gas exchange kinetics at the onset of exercise.
Six male subjects performed 120W exercise on a cycle ergometer for 7 min in the morning (AM; 7: 30-8: 30) and evening (PM; 16: 30-17: 30) . Rectal temperature (Tr) and mean skin temperature (Tsk) at rest were significantly higher PM than AM, the differences being 0.9±0.2°C and 0.7±0.2°C, respectively. Respiratory and circulatory parameters at rest and during exercise were not different between AM and PM. The time constants of oxygen uptake (Vo2), carbon dioxide output (Vco2), minute ventilation (VE), heart rate (HR), and oxygen pulse (Vo2/HR) showed the same results. There was no relationship between temperature parameters (Tr, Tsk) and the time constants.
It is suggested that circadian rhythms reflected by the change in body temperature do not have any effect on gas exchange kinetics at the onset of moderate bicycle exercise.
