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Bishop NC Scanlon GA Walsh NP McCallum LJ Walker GJ 《Journal of sports sciences》2004,22(11-12):1091-1098
Ingesting carbohydrate beverages during prolonged exercise is associated with fewer numbers of circulating neutrophils and attenuated neutrophil functional responses, yet there is little information about the effect of fluid intake alone on immune responses to prolonged exercise. The aim of this study was to examine the influence of regular fluid ingestion compared with no fluid ingestion on plasma cortisol, circulating neutrophil and lipopolysaccharide (LPS)-stimulated neutrophil degranulation responses to prolonged cycling. In a randomized design, nine recreationally active males cycled for 2 h at 65% VO2max on two occasions with either fluid ingestion (lemon-flavoured water, fluid trial) before and during the exercise, or with no fluid intake at all (no fluid trial). Venous blood samples were obtained at rest, immediately after exercise and 1 h after exercise. Immediately after exercise, the plasma cortisol concentration was significantly higher in the no fluid trial than in the fluid trial (592 +/- 62 vs 670 +/- 63 nmol x l(-1), P < 0.05). Circulating numbers of neutrophils increased 4.5-fold (P < 0.01) and LPS-stimulated elastase release per neutrophil decreased 34 +/- 7% (P < 0.01) immediately after exercise; there were no differences between trials. These results suggest that in ambient environmental conditions, fluid ingestion alone has a negligible effect on circulating neutrophil and LPS-stimulated neutrophil degranulation responses to prolonged exercise. 相似文献
997.
The effects of carbohydrate supplementation on immune responses to a soccer-specific exercise protocol 总被引:1,自引:0,他引:1
The aim of this study was to determine the effect of carbohydrate (CHO) versus placebo (PLA) beverage consumption on the immune and plasma cortisol responses to a soccer-specific exercise protocol in 8 university team soccer players. In a randomized, counterbalanced design, the players received carbohydrate or placebo beverages before, during and after two 90 min soccer-specific exercise bouts (3 days apart) designed to mimic the activities performed and the distance covered in a typical soccer match. Blood and saliva samples were collected before, during and after the exercise protocol. Plasma lactate concentration increased to approximately 4 mmol x l(-1) at 45 and 90 min of exercise in both treatments (P<0.01). Plasma glucose concentration was significantly lower after 90 min of exercise with ingestion of the placebo than the carbohydrate (PLA: 4.57+/-0.12 mmol x l(-1); CHO: 5.49+/-0.11 mmol x l(-1); P<0.01). The pattern of change in plasma cortisol, circulating lymphocyte count and saliva immunoglobulin A secretion did not differ between the carbohydrate and placebo trials. Blood neutrophil counts were 14% higher 1 h after the placebo trial than the carbohydrate trial (PLA: 4.8+/-0.5x10(9) cells x l(-1); CHO: 4.2+/-0.5x10(9) cells x l(-1); P = 0.06), but the treatment had no effect on the degranulation response of blood neutrophils stimulated by bacterial lipopolysaccharide. We conclude that, although previous studies have shown that carbohydrate feeding is effective in attenuating immune responses to prolonged continuous strenuous exercise, the same cannot be said for a soccer-specific intermittent exercise protocol. When overall exercise intensity is moderate, and changes in plasma glucose, cortisol and immune variables are relatively small, it would appear that carbohydrate ingestion has only a minimal influence on the immune response to exercise. 相似文献
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IQ-discrepancy definitions and the diagnosis of LD: introduction to the special issue 总被引:2,自引:0,他引:2
Siegel LS 《Journal of learning disabilities》2003,36(1):2-3
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在数字图书馆结构中融入知识组织系统 总被引:15,自引:4,他引:15
以亚历山大数字图书馆项目将数字图书馆馆藏、知识组织系统、服务设施在数字图书馆环境中互相配合的实践为例,讨论在数字图书馆结构中将知识组织系统作为有机的组成部分的意义和具体方法,提出数字图书馆和分类学研究两方面应该探索的新课题。 相似文献