CAFFEINE INFLUENCES ON EXERCISE AND PSYCHOLOGICAL STRESS

描述：这项工作的目标是发展一个基础 咖啡因对心血管和心脏的影响 休息、精神和运动时的神经内分泌功能 压力源。咖啡因被广泛用于具有重要药理意义的 数量。它会影响中枢神经系统、心血管系统 活跃性和神经内分泌功能。消费可能会在以下期间增加 精神紧张的时候，它经常出现在运动中。 咖啡因已被证明会增加心血管疾病的风险因素 如血清胆固醇和脂类成分。然而，潜在的 咖啡因的影响可能会因对咖啡因的耐受性而减弱 习惯性用户。 这个项目的目标是研究咖啡因对人体健康的影响 血压(BP)和皮质醇(CORT)在正常情况下较小 入口处。理解这种效应的减少对于正确地 评估咖啡因的生理作用和潜在的后果 健康。鉴于公众对咖啡因使用的关注，以及关于 负面的健康后果，重要的是要有一个良好的 关于咖啡因的影响和咖啡因的修饰的信息 人类的耐受性。容忍度将通过不同水平的 128年每天摄入量为0至600毫克(相当于6杯咖啡) 志愿者超过4周，并检查由此产生的修改 血压和皮质醇对急性咖啡因剂量的反应(3.3 Mg/kg)。咖啡因使血压和皮质醇升高的能力代表了它的两个 最普遍和最重要的生理影响，这些将是 正在研究的模型反应系统。 该项目有三个具体目标：第一，研究 对早晨挑战的急性(1小时)血压和皮质醇反应的耐受性 咖啡因的剂量；第二，测量耐受对血压和 急性应激(30分钟精神应激或运动)时的皮质醇反应 在早晨的激发剂量之后；第三，检查 一天动态血压对血压和皮质醇水平的耐受性 反复激发剂量后的监测。主要假设 经常摄入咖啡因会产生对咖啡因的部分耐受性 这一点可能因人而异。 这些信息将帮助我们在上下文中适当地评估 有证据表明咖啡因可以改变生理功能和 对压力的反应。

DESCRIPTION: The objective of this work is to develop a base of information about the effects of caffeine on cardiovascular and neuroendocrine functions during rest and during mental and exercise stressors. Caffeine is widely used in pharmacologically significant quantities. It affects the central nervous system, cardiovascular activity, and neuroendocrine function. Consumption may increase during times of mental stress, and it is often present during exercise. Caffeine has been shown to increase cardiovascular disease risk factors such as serum cholesterol and lipid fractions. However, the potential effects of caffeine may be reduced by development of tolerance in habitual users. The goal of this project is to examine whether caffeine's elevation of blood pressure (BP) and cortisol (CORT) is smaller following regular intake. Understanding this reduction of effect is essential to properly evaluate caffeine's physiological effects and potential consequences for health. In view of public concerns about caffeine use and reports of negative health consequences, it is important to have a well established body of information about caffeine's effects and their modification by tolerance in humans. Tolerance will be tested by varying levels of intake from 0 to 600 mg/day (equivalent to 6 cups of coffee) in 128 volunteers over 4 weeks and examining the resulting modifications of blood pressure and cortisol responses to an acute caffeine dose (3.3 mg/kg). Caffeine's ability to elevate BP and CORT represents two of its most pervasive and important physiological effects, and these will be the model response systems under study. This project has three specific aims: first to study the effect of tolerance on acute (1 hr) BP and CORT responses to a morning challenge dose of caffeine; second to measure the effect of tolerance on BP and CORT responses during acute stress (30 min mental stress or exercise) following the morning challenge dose; and third to examine the effect of tolerance on levels of BP and CORT during a day of ambulatory BP monitoring following a repeated challenge dose. The primary hypothesis is that regular intake of caffeine produces a partial tolerance to its effects, and that this may vary substantially from person to person. This information will help us to properly evaluate in context the evidence showing that caffeine can alter physiological functions and responses to stress.