Reliability of Exercise Cardiopulmonary Responses in Older Persons With Moderate-to-Heavy Chronic Disease Burdens

The purpose of the study was to assess the reliability of cardiopulmonary responses in older adults with moderate-to-heavy chronic disease burdens. Twenty-three participants were considered to have significant chronic disease burdens. The average age was 79 ± 7.9 (70 to 94) years. Each participant was initially tested and retested within 7 days of the initial test and at approximately the same time of day. The testing protocol consisted of a treadmill protocol developed in 1995. The protocol began at a speed of 1.5 mph and 0% incline, with the speed and incline increasing by 0.5 mph and 3.0% incline every 3 min. Respiratory gases were collected using standard gas collection techniques during rest, peak exercise, and recovery. The BMDP-PC statistical software package was utilized to conduct a one-sample repeated measures analysis of variance (participants-within-repeated-measures design). Intraclass correlation estimates of what reliability would be for a single measurement or trial were calculated. Reliability estimates of .90 or better were obtained for all resting, peak exercise, and recovery variables except peak respiratory quotient (RQ) and for recovery RQ and heart rate (i.e., R = .89, .89, and .76, respectively). These findings indicate that the measurement of cardiorespiratory values are very reliable in older persons with moderate-to-heavy chronic disease burdens.