Accelerometer-Determined Physical Activity and its Association with Self-Reported Health in a Population of Older Adults

Introduction Regular physical activity (PA) in older adults is critically important to ensure healthy aging. The link between PA and prevention of disease, maintenance of independence, and improved quality of life is supported by strong evidence. However, there is a lack of data on population levels of PA among older adults using objective PA assessment methods. Therefore, the aim of this study was to assess PA level objectively and to examine its association with self-reported health in a random national sample of older adults.

Methods The present study is a part of a national multicenter study involving 10 universities and university colleges in Norway. Participants for the initial study were randomly selected from the national population registry, and the current study includes those of the initial sample aged 65-85 years. The ActiGraph GT1M accelerometer was used to assess PA for seven consecutive days. Overall PA levels, adjusted for test center, are presented as counts per minute (cpm). A questionnaire was used to register self-reported health. Univariate analysis of variance with Bonferroni post-hoc tests were used for the analysis of multiple comparisons.

Results A total of 560 participants fulfilled the accelerometer data inclusion criteria (at least four days or more of at least 10 hours of daily activity registration). Mean age (SD) was 71.8 (5.6) y for women (n=282) and 71.7 (5.2) y for men (n=278). No sex differences in overall PA were observed. Mean (SEM) overall PA levels were as follows: 65-69 y 317 (9) cpm, 70-74 y 301 (12) cpm, 75-79 y 237 (14) cpm, and 80-85 y 160 (18) cpm. This accounted for a reduction in overall PA of 5%.

Conclusion PA level among older adults living in Norway decreased with increasing age, and the oldest (80-85 y) displayed a 50% lower activity level compared to the youngest (65-70 y). Overall PA levels were associated with self-reported health.