Promoting physical activity for elders with compromised function: the lifestyle interventions and independence for elders (LIFE) study physical activity intervention

Abstract

The Lifestyle Interventions and Independence for Elders (LIFE) Study is a Phase III randomized controlled clinical trial (Clinicaltrials.gov identifier: NCT01072500) that will provide definitive evidence regarding the effect of physical activity (PA) on major mobility disability in older adults (70-89 years old) who have compromised physical function. This paper describes the methods employed in the delivery of the LIFE Study PA intervention, providing insight into how we promoted adherence and monitored the fidelity of treatment. Data are presented on participants' motives and self-perceptions at the onset of the trial along with accelerometry data on patterns of PA during exercise training. Prior to the onset of training, 31.4% of participants noted slight conflict with being able to meet the demands of the program and 6.4% indicated that the degree of conflict would be moderate. Accelerometry data collected during PA training revealed that the average intensity - 1,555 counts/minute for men and 1,237 counts/minute for women - was well below the cutoff point used to classify exercise as being of moderate intensity or higher for adults. Also, a sizable subgroup required one or more rest stops. These data illustrate that it is not feasible to have a single exercise prescription for older adults with compromised function. Moreover, the concept of what constitutes "moderate" exercise or an appropriate volume of work is dictated by the physical capacities of each individual and the level of comfort/stability in actually executing a specific prescription.

Keywords: accelerometry; aging; compromised physical function; older adults; physical disability.

Figures

Figure 1

Panels (A–C) represent three representative accelerometry recordings from center-based exercise training. Notes: In (A–C), the y-axis represents counts/minute, whereas the x-axis is the minute-by-minute time course for the training bout. The horizontal red “+” marks represent the median counts/minute achieved across the activity session; the blue circles represent the counts achieved for a given minute of activity; the horizontal blue “+” marks indicate rest periods and identify the number of the rest period with a numeric superscript, if any rest intervals were taken. The participant in Figure 1A is exercising well above the standard adult cutoff point for moderate-intensity exercise (2,690 counts/minute21) and has a very consistent pace across the entire exercise bout. The participants in Figure 1B and C have median activity counts well below the adult cutoff point for moderate PA with the individual in Figure 1C being the most compromised. Note that the person in Figure 1B exhibits a high degree of variability in intensity and had to take a 6-min rest stop. Such patterns are common for participants with joint pain or various chronic health conditions.