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利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 了解能量消耗(EE)随年龄的变化对于确定如何在老年时保持健康体重很重要。这项拟议的初步研究的目的是确定健康、正常体重的男性和女性对急性运动反应的EE变化是否受年龄的影响。我们假设，与中青年相比，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)的更大下降和静息代谢率(RMR)的较小增长。我们还将确定急性运动后EE的变化是否与调节激素的变化有关，包括瘦素和甲状腺激素。五(5)名男性和5名女性将被招募到三个年龄组中的一个：年轻、中年和老年。SPA、RMR和激素水平将在急性运动之前、之后立即和24小时后进行测量。SPA将使用RT3加速度计测量，RMR将使用间接量热法测量。作为潜在的协变量，卡路里摄入量将使用1天和4天的食物记录进行分析，身体成分将使用DXA确定。在调整混杂因素后，运动前、运动后和改变后的数值将在不同年龄组之间进行比较。这项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.