Physical Activity Monitoring In the LIFE Study Using the

在LIFE试点研究中，被分配到运动组的参与者的主要干预措施将是散步。根据治疗方案，在前六个月内，他们增加的步行量将达到一半。在家吗?或者在一个没有监督的环境中。在接下来的六个月里，对于大多数参与者来说，至少75%的指定步行将是无人监督的。为了知道这种干预是否完成，LIFE的调查人员需要证明运动组的参与者与健康衰老组的参与者相比，步行量显著增加。目前的方案包括使用计步器、日志和CHAMPS问卷来告知研究人员每个研究参与者的活动概况。虽然所有这些测量工具都可能提供有用的数据，但没有一种被证明能够准确客观地评估老年人的日常身体活动情况。Actigraph是一款小型固态加速度计/记录仪（6.6 x 4.3 x 2.5 cm.， 70克），可以连续存储移动次数x运动变化率（加速度）长达一个月（大约电池寿命）。它存储这些？计数？对于指定的时间间隔，通常设置为一分钟。对于LIFE，该监测器将佩戴在每个参与者的右臀部。

The major intervention in the LIFE pilot study for participants assigned to the exercise group will be walking. According to the treatment protocol, during the first six months as much as half of their increase in walking will be carried out ?at home? or in a non-supervised setting. During the second six months, at least 75% of the assigned walking will be non-supervised for most participants. To know if this intervention was accomplished, LIFE investigators need documentation that a significant increase in walking took place in the exercise participants versus the healthy aging class participants. Currently the protocol includes the use of pedometers, logs and the CHAMPS questionnaire to inform the investigators about the activity profile of each study participant. While all of these measurement tools are likely to provide useful data, none have been proven to provide an accurate and objective assessment of the daily physical activity profile of older, somewhat frail persons. The Actigraph is a small solid-state accelerometer/recorder (6.6 x 4.3 x 2.5 cm., 70 grams) that can store the number of times it moves x the rate of movement change (acceleration) on a continuous basis for up to a month (approximate battery life). It stores these ?counts? for specified times intervals, usually set at one-minute. For LIFE, this monitor will be worn on the right hip of each participant. The specific aims of this project are to determine the capability of the Actigraph accelerometer activity monitor to detect a significant difference in the physical activity level in a subset of subjects assigned to the LIFE exercise group versus the healthy aging class controls at six months into the study, (2) compare the assessment of amount of physical activity performed by a subset of subjects in the two treatment groups as determined by the CHAMPS physical activity questionnaire administered at 6 months and the Actigraph monitor using average number of ?accelerometer counts? per hour and number of minutes per day spent above a conditioning threshold, and (3) determine if data collected by the Actigraph monitor during the 400-meter walk at the 6-month evaluation can be used to help ?calibrate? or individualize the analysis of the Actigraph recorded during the 7 days of usual living.