NORMAL AGING AND VENTILATORY LIMITS TO PERFORMANCE

这项研究的目的是确定正常的下降是否在 随年龄增长的肺功能对 健康非吸烟老年男性体能训练中的通风 还有女人。研究的具体目的是： 1.确定最大运动期间的通风是否为机械性的 仅限于老年男性和女性。我们假设正常的下降 最大呼气流量和肺容量的年龄相关性变化 将对通风施加机械限制，这将得到证明 通过显著的呼气气流限制和通过最小限度的增加 最大通气量，与年轻受试者相比，在换气时 在运动中通过呼吸3%的混合气体来增加需求 二氧化碳、21%氧气和76%氮气。这些研究还将讨论其后果 老年人对运动能力的增加的通风需求。 2.确定正常肺功能是否随年龄增长而下降 运动时会影响呼气末肺活量。我们假设 老化会对通风造成机械约束，这将导致 运动时呼气末肺活量增加。此外， 我们认为呼气末肺活量的增加在 运动将与呼气气流受限有关，将 发生在较低水平的运动中，即通过 呼吸3%二氧化碳、21%氧气和76%氮气的混合气体，将是 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检验这些假设， 动态流量-容量和压力-容量环、呼吸模式、肺 呼吸室内空气和空气时的体积、气体交换和运动能力 当呼吸循环中含有3%二氧化碳、21%氧气和76%氮气的混合气体时 测功术。我们将对两个年龄段的21名男性和16名女性进行研究： 35-45岁和65-75岁。静态肺力学，最大流量-容量环， 并将测得的等容压力流量曲线静置以确定 呼吸力学中与年龄相关的变化，可能是机械性的 在运动过程中影响肺功能。

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.