AGE-RELATED DIFFERENCES IN ENERGY EXPENDITURE IN RESPONSE TO ACUTE EXERCISE

这个子项目是许多研究子项目中的一个 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， 因此可以在其他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。 了解能量消耗（EE）随年龄增长的变化对于确定如何在老年时保持健康的体重非常重要。这项拟议的试点研究的目的是确定是否在EE的变化，在急性运动的健康，正常体重的男性和女性的年龄的影响。我们假设，与中年和年轻人相比，一次45分钟的中等强度运动将导致老年人自发体力活动（SPA）的较大下降和静息代谢率（RMR）的较小增加。我们还将确定急性运动后EE的变化是否与调节激素（包括瘦素和甲状腺激素）的变化有关。将招募5名男性和5名女性，分为三个年龄组：青年、中年和老年。将在急性运动回合之前、之后立即和之后24小时测量SPA、RMR和激素水平。SPA将使用RT 3加速度计测量，RMR将使用间接量热法测量。作为潜在协变量，将使用1天和4天的食物记录分析热量摄入，并使用DXA测定身体组成。在调整混杂因素后，将比较不同年龄组的运动前、运动后和变化值。本研究的结果将开始阐明年龄对运动后EE变化的影响。

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. Understanding changes in energy expenditure (EE) with aging is important in determining how to maintain a healthy weight at old age. The purpose of this proposed pilot study is to determine whether changes in EE in response to acute exercise are influenced by age in healthy, normal weight men and women. We hypothesize that a single 45-minute session of moderate-intensity exercise will result in a larger decline in spontaneous physical activity (SPA) and a smaller increase in resting metabolic rate (RMR) in older compared to middle-aged and younger individuals. We will also determine whether changes in EE in response to acute exercise are related to changes in regulatory hormones, including leptin and thyroid hormones. Five (5) men and 5 women will be recruited into one of three age groups: young, middle-aged, and old. SPA, RMR, and hormone levels will be measured before, immediately after and 24 hours after the acute exercise bout. SPA will be measured using a RT3 accelerometer and RMR will be measured using indirect calorimetry. As potential covariates, caloric intake will be analyzed using 1- and 4-day food records and body composition will be determined using DXA. Pre-exercise, post-exercise, and change values will be compared between age groups, after adjusting for confounding factors. The results from this study will begin to clarify the effects of age on changes in EE in response to exercise.