Effects of Continuous and Discontinuous Running Exercise on Cortisol and Immune Functions

Autor: Mong-Da Hsu, 徐孟達
Rok vydání: 2002
Druh dokumentu: 學位論文 ; thesis
Popis: 90
Purpose: The purpose of this study was to examine the effects of continuous and discontinuous running exercise on cortisol and immune functions. Method: Thirty university male students (age=20.80±1.49 years, VO2max values=44.57±6.23 ml/min-1．kg-1) were recruited as the subjects for this study. They were divided into three different groups according to VO2max values: continuous exercise group (CEG), discontinuous exercise group (DEG) and control group (CG). The CEG performed single bout of treadmill exercise lasting 30 minutes at 70% VO2R at 13:00 (3 times/wk, 1wk). The DEG performed two bouts of treadmill exercise lasting 15 minutes at 70% VO2R at 9:00 and 13:15 (3 times/wk, 1wk). Blood samples were collected at rest before exercise, 0 hour, 2 hours and 24 hours after exercise. Cortisol, leucocyte count, neutrophil count, lymphocyte count, peripheral mononuclear cell (PMNC) proliferation, and cytokines were measured. Data were analyzed using mixed design two-way ANOVA and repeated one-way ANOVA. Results: 1) Circadian rhythm could influence cortisol concentration significantly, but there was no difference on cortisol between each group. 2) Leucocyte count, neutrophil count, lymphocyte count of CEG were significantly higher, but PMNC proliferation was lower (p< .05) at 0 hour after exercise than the DEG and CG. 2) Neutrophil count of CEG was still higher, but lymphocyte count was lower (p< .05) at 2 hours after exercise than the other groups. 3) There was no difference on cytokines between each group. Conclusions: Circadian rhythm could influence cortisol concentration significantly. During the whole period of testing, the lymphocyte count and PMNC proliferation of CEG were lower within two hours after exercise and may temporarily depress the subjects’ immune function. However, the subjects of DEG and CG didn’t show any depression of the immune variables after exercise.
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