Relationship between sympathetic and adrenomedullary activities during exercise. With reference to duration of exercise.
- VernacularTitle:運動時の交感神経と副腎髄質の相対的活動度の変化 運動持続時間との関連
- Author:
NOBUHARU FUJII
;
YUSHIN KITANO
;
YOSHIYUKI FUKUOKA
;
RYOKO SONE
;
HARUO IKEGAMI
- Publication Type:Journal Article
- Keywords:
sympathetic activity;
adrenomedullary activity;
ratio of noradrenaline to adrenaline;
exercise duration
- From:Japanese Journal of Physical Fitness and Sports Medicine
1992;41(5):567-575
- CountryJapan
- Language:Japanese
-
Abstract:
This study was designed to evaluate the effect of exercise duration on the relation between sympathetic and adrenomedullary activities. Six trained subjects completed the following two exercise protocols ; six 2-min exercise sessions at 100% maximal O2uptake (VO2max) interspersed with 10-min recovery periods, and three 10-min exercise sessions at 80%VO2max interspersed with 10-min recovery periods. Plasma noradrenaline (NA), plasma adrenaline (A), NA/A ratio (NA/A), heart rate (HR), coefficient of variation of R-R intervals (CVRR) and blood lactate (La) were measured. With repetition of exercise sessions in both protocols, HR, NA and A gradually increased. CVRR rapidly decreased at the first exercise session and remained unchanged thereafter. NA/A increased by the first exercise session, but decreased by the following exercise sessions. NA in the second exercise session at 100%VO2max was significantly lower than that in the first. We conclude that, at the beginning of exercise, the increase of sympathetic activity is more dominant than that of adrenomedullary activity, whereas, with prolongation of exercise duration, the increase of adrenomedullary activity becomes more dominant than that of sympathetic activity,
