THE EFFECTS OF MODERATE- AND HIGH-INTENSITY EXERCISE ON VASCULAR FUNCTION

这个子项目是许多利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 心血管疾病是一个主要的健康问题，在很大程度上可以通过改变生活方式来预防，例如增加体育活动。 尽管我们清楚地了解与久坐不动的生活方式相关的风险，但大多数美国人并不符合维持心血管健康的推荐体力活动指南。 内皮功能障碍被认为是动脉粥样硬化发展的早期发生，其存在和严重程度与未来心脏病发病率和死亡率高度相关。 血管内皮不能响应于正常刺激产生血管扩张剂NO导致血管张力和炎症的调节受损。 在对健康个体和具有高风险或临床诊断的心血管疾病的人的研究中，运动训练已被证明对内皮功能具有有益作用。 本研究的目的是确定运动强度对精瘦和腹部肥胖个体FMD急性变化的影响。 这项研究将是第一个检查急性时程FMD测量后，一轮的运动。 我们假设，与中等强度运动相比，30分钟高强度运动后FMD的增加幅度和持续时间更大，并且在健康体重和肥胖成年人中都会观察到这种急性运动效应（但在肥胖者中可能会减弱）。 作为次要目的，将使用多普勒超声和使用Depletion微泡的造影剂增强检查高强度运动后下肢微血管和大血管变化的时间。 这些结果将有助于我们了解运动对内皮功能、全身和微血管血流的影响所涉及的因素，并可能为那些有CVD风险的人提供更具体的运动处方。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Cardiovascular disease is a major health problem that is largely preventable through lifestyle modifications, such as increasing physical activity. Despite our clear understanding of the risks associated with a sedentary lifestyle, most Americans do not meet the recommended physical activity guidelines for maintaining cardiovascular health. Endothelial dysfunction is recognized as an early occurrence in the development of atherosclerosis, and its presence and severity are highly correlated with future cardiac morbidity and mortality. Failure of the vascular endothelium to produce the vasodilator NO in response to normal stimuli results in the impaired regulation of vascular tone and inflammation. Exercise training has been demonstrated to have beneficial effects on endothelial function in studies of both healthy individuals and those with an elevated risk or clinically diagnosed cardiovascular disease. The purpose of the current study is to determine the effect of exercise intensity on the acute changes in FMD in both lean and abdominally obese individuals. This study will be the first to examine the acute time course FMD measurements following a single bout of exercise. We hypothesize that the augmentation of FMD will be of greater magnitude and duration following 30 minutes of high-intensity compared with moderate-intensity exercise, and that this acute exercise effect will be observed in both healthy weight and obese adults (but may be attenuated in the obese). As a secondary aim, the timing of microvascular and macrovascular changes in the lower limb immediately following high-intensity exercise will be examined using Doppler ultrasound and contrast enhancement with Definity microbubbles. The results will contribute to our understanding of the factors involved in the effects of exercise on endothelial function, and systemic and microvascular blood flow, and may lead to more specific exercise prescription for those at risk for CVD.