Physical activity among community-dwelling older adults : relationships with body composition and physical capacity, and the effects of physical and cognitive training, multimorbidity patterns, and executive functions

Abstract

While physical activity has a wide range of benefits for older adults’ health and functioning, most older adults are physically inactive. Health status and the cognitive processes required for planned and goal-oriented behavior, known as executive functions, may determine physical activity. This dissertation research investigated the associations of physical activity with body composition and physical capacity in older adults. It also explored the effect of physical and cognitive training on physical activity compared to physical training alone and the impact of executive functions and multimorbidity patterns on the intervention effects. The data were drawn from a 12-month randomized controlled trial, the PASSWORD study, with follow-ups after one-year and during COVID-19 pandemic. Participants (n=314) were physically inactive 70- to 85-year-old residents of Jyväskylä, Finland. They were randomized to receive either a physical training intervention, including supervised and home-based strength, walking and balance exercises, or the same physical training intervention plus computerized executive functions training. Data were collected by questionnaires, accelerometry, laboratory measurements, and registers. The results showed that physical activity of any intensity was associated with lower fat percent and faster walking speed, whereas light-intensity activity only was associated positively with bone traits, and the higher intensities only with lower extremity functioning. Physical and cognitive training did not add to the effects on physical activity over physical training alone, whereas higher executive functions at baseline predicted higher physical activity. Physical activity increased in both study groups and was maintained at a higher than baseline level during the follow-up. Multimorbidity patterns had a small impact on physical activity and capacity, while the direction and magnitude of the impact of different chronic conditions varied, with most remaining insignificant. Thus, even very low-intensity physical activity may be beneficial for older adults, and sustained changes in physical activity can be achieved with multicomponent physical training. While multimorbidity may not substantially impact training outcomes, higher executive functions may facilitate the adoption of a physically active lifestyle.