NORMAL AGING AND VENTILATORY LIMITS TO PERFORMANCE

这项研究的目的是确定是否正常下降， 随着年龄的增长，肺功能受到机械限制， 健康非吸烟老年男性体力活动时的通气 和妇女 研究的具体目标是： 1.确定最大运动时的通气是否是机械性的， 仅限于老年男女。 我们假设正常的下降 最大呼气流量和肺容量的年龄相关变化 将对通风施加机械限制， 通过显著的呼气气流限制和通过最小的增加， 最大通气量，与年轻受试者相比， 在运动过程中，通过呼吸含有3%的气体混合物来增加需求。 CO2，21% O2和76% N2。 这些研究也将解决后果 对老年人运动能力的增强的补充需求。 2.为了确定肺功能是否随着年龄的增长而正常下降 影响运动时呼气末肺容量。 我们假设 老化会对通风造成机械限制， 运动时呼气末肺容量增加。 此外，委员会认为， 我们认为，在呼气末肺容量的增加， 运动将与呼气气流限制有关， 在较低水平的运动时， 呼吸3%CO2、21%O2和76%N2的混合气体， 与年龄相关的最大运动能力下降有关。 我们建议通过确定最大通气量来测试这些假设， 动态流量-容积和压力-容积循环、呼吸模式、肺 呼吸室内空气时的体积、气体交换和运动能力， 当在循环期间呼吸含3% CO2、21% O2和76% N2的气体混合物时 测力法 我们将研究两个年龄组中的21名男性和16名女性： 35-45和65-75岁 静态肺力学，最大流量-容量环， 将在静止时测量等容压力流量曲线，以确定 与年龄相关的呼吸力学变化， 在运动中损害肺功能。

The purpose of this study is to determine if the normal decline in pulmonary function with aging imposes mechanical limitations to ventilation during physical performance in healthy nonsmoking elderly men and women. The specific aims of the research are: 1. To determine if ventilation during maximal exercise is mechanically limited in elderly men and women. We hypothesize that the normal decline in maximal expiratory flow and the age-related changes in lung volumes will impose mechanical constraints to ventilation which will be evidenced by marked expiratory airflow limitation and by a minimal increase in maximal ventilation, as compared to younger subjects, when ventilatory demand is augmented during exercise by breathing a gas mixture with 3% CO2, 21% O2, and 76% N2. These studies will also address the consequence of augmented ventilatory demand on exercise capacity in the elderly. 2. To determine if the normal decline in pulmonary function with aging affects end-expiratory lung volume during exercise. We hypothesize that aging will impose mechanical constraints to ventilation which will result in an increased end-expiratory lung volume during exercise. Furthermore, we propose that the increase in end-expiratory lung volume during exercise will be associated with expiratory airflow limitation, will occur at lower levels of exercise when ventilation is augmented by breathing a gas mixture of 3% CO2, 21% O2, and 76% N2, and will be associated with the age-related decline in maximal exercise capacity. We propose to test these hypotheses by determining maximal ventilation, dynamic flow-volume and pressure-volume loops, breathing pattern, lung volumes, gas exchange, and exercise capacity when breathing room air and when breathing a gas mixture with 3% CO2, 21% O2, and 76% N2 during cycle ergometry. We will study 21 men and 16 women in each of two age-groups: 35-45 and 65-75 yr. Static lung mechanics, maximal flow-volume loops, and isovolume pressure flow curves will be measured at rest to determine age related changes in respiratory mechanics that could mechanically compromise pulmonary function during exercise.