Purpose: We investigated the effect of menstrual cycle on the cardiovascular responses during recovery period from exercise. 10 healthy women were participated in the early follicular phase (EP: low estrogen and low p...Purpose: We investigated the effect of menstrual cycle on the cardiovascular responses during recovery period from exercise. 10 healthy women were participated in the early follicular phase (EP: low estrogen and low progesterone: 1 - 4 days) and the late follicular phase (LP: high estrogen and low progesterone: 10 - 13 days) during menstrual cycle. Methods: All subjects completed a graded cycling exercise testing to determine the relative exercise intensity. All subjects were assessed systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR), stroke volume (SV), cardiac output (CO), and total vascular conductance (TVC) at resting and during recovery period from moderated cycling exercise during EP and LP. Results: During EP, compared with LP, resting SBP and MAP were higher and TVC was lower (p p Conclusions: This study could be increased the peripheral vasoconstriction in low estrogen levels. And during early follicular phase with low estrogen level, it may maintain an increased blood pressure during recovery period following cycling. We suggest that the timing of the menstrual cycle should be considered when measuring blood pressure during clinical exercise testing.展开更多
Inspiratory-muscle fatigue （IMF） may occur after long-duration or continuous short-duration exercise and may limit exercise performance. Daily athletics training is often intermittent, but it is unclear if intermitt...Inspiratory-muscle fatigue （IMF） may occur after long-duration or continuous short-duration exercise and may limit exercise performance. Daily athletics training is often intermittent, but it is unclear if intermittent running induces IMF. We investigated IMF after a maximal anaerobic running test （MART） and maximal intermittent graded exercise test. Nine female middle-distance （400 or 800 m） runners performed MART and maximal intermittent graded exercise tests. Maximal inspiratory pressure （MIP） was measured before and after each test using a portable autospirometer. There was no significant difference in mean MIPs before （105 ± 24 cm H2O） and after （104 ± 28 cm H2O） the MART （P = 0.95, effect size [ES] as partial η2 = 0.01）. Mean M IP after the maximal intermittent graded exercise test （97 ± 26 cm H2O） was lower than before exercise （105 ± 27 cm H2O） （P = 0.01, 1]2 = 0.83） Mean IMF was higher for the maximal intermittent graded exercise test （8.5 ± 4.2 cm H2O） than for the MART （0.8 ± 4.1 cm H2O） （P = 0.01, ES as Cohen＇s d = 1.88）. IMF occurs after relatively long-duration intermittent running exercise. Coaches may consider recommending inspiratory-muscle training or warm-up to reduce IMF resulting from relatively long-duration intermittent running exercise.展开更多
Background It is well known that dehydration can impair bodily functions. To evaluate the impact of hydration status under ambient environmental temperature on the immune system, 25 male collegiate wrestlers were recr...Background It is well known that dehydration can impair bodily functions. To evaluate the impact of hydration status under ambient environmental temperature on the immune system, 25 male collegiate wrestlers were recruited to undergo an experimental dehydration program.Methods Thirteen subjects had controlled diets with individual energy requirements to prevent body mass loss and restricted water intake to cause 4.52% dehydration; they formed the dehydrated group （DE）. These subjects developed a urine specific gravity of about 1.030 in 84 hours. Twelve other subjects had no water restriction and maintained their total body weight comprised the euhydrated group （EU）. Peripheral blood monocytes （PBMNC） were isolated after dehydration to perform immune response testing by being incubated with a polysaccharide fraction from fu-ling, Poria cocos （polysaccharide fraction from Poria cocos, PCPS, 1-30 μg/L）, to prepare a conditioned medium termed conditioned medium of PBMNC stimulated by PCPS （PCPS-MNC-CM）. More PCPS （25 μg/L） was needed in the DE group to prepare the PCPS-MNC-CM, which was assayed with a growth inhibitory curve for treated U973 cells.Results The treated U937 cells, incubated together with PCPS-MNC-CM from the DE group, exhibited a much lower nitroblue tetrazolium （NBT） positive value of （63.7±4.7）%. The concentration of interferon-gamma （IFN-Y）, interleukin （IL）-1β and tumor necrosis factor （TNF）-α in PCPS-MNC-CM from subjects after dehydration was much lower than in the CM from the EU group.Conclusion The immune response to PCPS in the DE group was lower than in normally hydrated subjects.展开更多
Background Both athletes with intensive exercise and aged people may have weakened immunity against virus infection. This study aimed to evaluate whether people undergoing aerobic exercises including competitive cycli...Background Both athletes with intensive exercise and aged people may have weakened immunity against virus infection. This study aimed to evaluate whether people undergoing aerobic exercises including competitive cyclists with moderate training （CMT） and middle-aged people practicing Tai Chi Chuan （TCC） exercise have higher immunity against hepatitis B virus than age-matched sedentary controls including college students （CSC） and middle-aged people （MSC）. Methods Human peripheral blood mononuclear cells from competitive cyclists and sedentary controls were stimulated by phytohemagglutinin （PHA） to prepare conditioned medium （MNC-CM） for the assessment of inhibitory effects on hepatitis B surface antigen （HBsAg） expression in human hepatoma Hep3B cells. Results The inhibitory effects on the relative HBsAg expression of CMT＇s and TCC＇s MNC-CM were greater than those of the controls. The CMT＇s MNC-CM prepared from 5 μg/ml PHA decreased HBsAg expression to 61.5%, whereas that of CSC remained at 83.8%. Similarly, this expression by treatment of TCC group＇ MNC-CM was 68.4% whereas that of MSC group was 84.3%. The levels of cytokines such as interferon-γ（IFN-γ）, tumor necrosis factor-α （TNF-α）, IFN-α and interleukin-1β （IL-1β） in the MNC-CM from the CMT and TCC groups were greater than those in the controls. Antibody neutralization of CMT＇s MNC-CM and addition of recombinant cytokines into CSC＇s MNC-CM indicated that IFN-γ, TNF-α and IFN-α had synergistic effects against HBsAg expression. Similar blocking effect was noted in TCC versus MSC groups. Conclusion These results suggest that the immunomodulatory response to suppress HBsAg expression in CMT and TCC with moderate aerobic exercise is greater than that in age-matched sedentary controls.展开更多
文摘Purpose: We investigated the effect of menstrual cycle on the cardiovascular responses during recovery period from exercise. 10 healthy women were participated in the early follicular phase (EP: low estrogen and low progesterone: 1 - 4 days) and the late follicular phase (LP: high estrogen and low progesterone: 10 - 13 days) during menstrual cycle. Methods: All subjects completed a graded cycling exercise testing to determine the relative exercise intensity. All subjects were assessed systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR), stroke volume (SV), cardiac output (CO), and total vascular conductance (TVC) at resting and during recovery period from moderated cycling exercise during EP and LP. Results: During EP, compared with LP, resting SBP and MAP were higher and TVC was lower (p p Conclusions: This study could be increased the peripheral vasoconstriction in low estrogen levels. And during early follicular phase with low estrogen level, it may maintain an increased blood pressure during recovery period following cycling. We suggest that the timing of the menstrual cycle should be considered when measuring blood pressure during clinical exercise testing.
文摘Inspiratory-muscle fatigue （IMF） may occur after long-duration or continuous short-duration exercise and may limit exercise performance. Daily athletics training is often intermittent, but it is unclear if intermittent running induces IMF. We investigated IMF after a maximal anaerobic running test （MART） and maximal intermittent graded exercise test. Nine female middle-distance （400 or 800 m） runners performed MART and maximal intermittent graded exercise tests. Maximal inspiratory pressure （MIP） was measured before and after each test using a portable autospirometer. There was no significant difference in mean MIPs before （105 ± 24 cm H2O） and after （104 ± 28 cm H2O） the MART （P = 0.95, effect size [ES] as partial η2 = 0.01）. Mean M IP after the maximal intermittent graded exercise test （97 ± 26 cm H2O） was lower than before exercise （105 ± 27 cm H2O） （P = 0.01, 1]2 = 0.83） Mean IMF was higher for the maximal intermittent graded exercise test （8.5 ± 4.2 cm H2O） than for the MART （0.8 ± 4.1 cm H2O） （P = 0.01, ES as Cohen＇s d = 1.88）. IMF occurs after relatively long-duration intermittent running exercise. Coaches may consider recommending inspiratory-muscle training or warm-up to reduce IMF resulting from relatively long-duration intermittent running exercise.
文摘Background It is well known that dehydration can impair bodily functions. To evaluate the impact of hydration status under ambient environmental temperature on the immune system, 25 male collegiate wrestlers were recruited to undergo an experimental dehydration program.Methods Thirteen subjects had controlled diets with individual energy requirements to prevent body mass loss and restricted water intake to cause 4.52% dehydration; they formed the dehydrated group （DE）. These subjects developed a urine specific gravity of about 1.030 in 84 hours. Twelve other subjects had no water restriction and maintained their total body weight comprised the euhydrated group （EU）. Peripheral blood monocytes （PBMNC） were isolated after dehydration to perform immune response testing by being incubated with a polysaccharide fraction from fu-ling, Poria cocos （polysaccharide fraction from Poria cocos, PCPS, 1-30 μg/L）, to prepare a conditioned medium termed conditioned medium of PBMNC stimulated by PCPS （PCPS-MNC-CM）. More PCPS （25 μg/L） was needed in the DE group to prepare the PCPS-MNC-CM, which was assayed with a growth inhibitory curve for treated U973 cells.Results The treated U937 cells, incubated together with PCPS-MNC-CM from the DE group, exhibited a much lower nitroblue tetrazolium （NBT） positive value of （63.7±4.7）%. The concentration of interferon-gamma （IFN-Y）, interleukin （IL）-1β and tumor necrosis factor （TNF）-α in PCPS-MNC-CM from subjects after dehydration was much lower than in the CM from the EU group.Conclusion The immune response to PCPS in the DE group was lower than in normally hydrated subjects.
文摘Background Both athletes with intensive exercise and aged people may have weakened immunity against virus infection. This study aimed to evaluate whether people undergoing aerobic exercises including competitive cyclists with moderate training （CMT） and middle-aged people practicing Tai Chi Chuan （TCC） exercise have higher immunity against hepatitis B virus than age-matched sedentary controls including college students （CSC） and middle-aged people （MSC）. Methods Human peripheral blood mononuclear cells from competitive cyclists and sedentary controls were stimulated by phytohemagglutinin （PHA） to prepare conditioned medium （MNC-CM） for the assessment of inhibitory effects on hepatitis B surface antigen （HBsAg） expression in human hepatoma Hep3B cells. Results The inhibitory effects on the relative HBsAg expression of CMT＇s and TCC＇s MNC-CM were greater than those of the controls. The CMT＇s MNC-CM prepared from 5 μg/ml PHA decreased HBsAg expression to 61.5%, whereas that of CSC remained at 83.8%. Similarly, this expression by treatment of TCC group＇ MNC-CM was 68.4% whereas that of MSC group was 84.3%. The levels of cytokines such as interferon-γ（IFN-γ）, tumor necrosis factor-α （TNF-α）, IFN-α and interleukin-1β （IL-1β） in the MNC-CM from the CMT and TCC groups were greater than those in the controls. Antibody neutralization of CMT＇s MNC-CM and addition of recombinant cytokines into CSC＇s MNC-CM indicated that IFN-γ, TNF-α and IFN-α had synergistic effects against HBsAg expression. Similar blocking effect was noted in TCC versus MSC groups. Conclusion These results suggest that the immunomodulatory response to suppress HBsAg expression in CMT and TCC with moderate aerobic exercise is greater than that in age-matched sedentary controls.
