Original research
Light physical activity is positively associated with cognitive performance in older community dwelling adults

https://doi.org/10.1016/j.jsams.2016.02.002Get rights and content

Abstract

Objectives

To evaluate the associations between an objective measure of different intensities of physical activity, upper- and lower-limb muscle strength and psychomotor performance and set-shifting domains of cognitive executive function in older adults.

Design

A cross-sectional study.

Methods

From the Tasmanian Older Adult Cohort Study, 188 community-dwelling older adults (53.7% female; mean age ± SD 63.98 ± 7.3 years) undertook 7-day physical activity behaviour monitoring using an accelerometer. Dynamometers were used to assess leg extension strength. The Trail Maker Tests were used to measure psychomotor processing speed and set-shifting performance.

Results

When controlling for age, smoking history, alcohol intake, educational achievement and neuropsychological functioning, higher levels of light physical activity, but not sedentary behaviour or moderate or vigorous physical activity, was found to be associated with better set-shifting performance. Neither physical activity behaviour or muscle strength were found to be associated with psychomotor performance. In addition, older age, greater alcohol intake, and lower levels of educational attainment, verbal learning and memory performance were significantly associated with lower scores on the set-shifting task; whereas older age and reduced neuropsychological functioning were associated with lower psychomotor processing speed scores.

Conclusions

Light physical activity is associated with higher executive functioning in community-dwelling older adults and this strengthens the evidence supporting exercise as a neuroprotective agent. Further studies are needed to understand why light physical activity behaviour positively influences executive functioning, and how such physical activity can be implemented into the daily routine of older adults.

Introduction

Participation in physical activity (PA) by older adults reduces the risk of chronic disease, and encourages the maintenance of muscle strength1 and functional independence.2 It is also possible that regular PA might delay the age-related decline in cognitive function.2

The collective evidence demonstrates PA positively influences cognition across a range of domains.3 A meta-analysis of prospective studies that examined the association between PA and cognitive decline in older adults found a low to moderate level of PA significantly (−35%) reduced the risk of decline.4 Others found an inverse relationship between increased muscle strength5 and cardiorespiratory fitness6 and cognitive decline.

Questionnaires and other self-report measures have historically been used to derive population-based measurements of habitual PA, despite their limited reliability and validity.7 Objective measures of PA are furthering our understanding of the association between cognition and PA, and there is emerging evidence cognitive function is improved by both light8 and moderate-to-vigorous PA.8, 9

Further population-based studies are required to clarify the association between cognition, muscle strength and objectively measured PA behaviours. In an ageing Australian population, understanding this association might aid the development of interventions aimed towards delaying or slowing the rate of cognitive decline. The aim of this study was to investigate cross-sectional associations between different intensities of PA, muscle strength and executive functioning as indexed by set-shifting and psychomotor performance in older adults. It was hypothesised that more active and stronger participants would have enhanced set-shifting and faster psychomotor speed whereas increased sedentary time would be associated with poorer set-shifting and psychomotor performance.

Section snippets

Method

Participants were drawn from the Tasmanian Older Adult Cohort (TASOAC), an ongoing, prospective, population-based study of community-dwelling older adults. An equal number of men and women between the ages of 50 and 79 years were randomly selected from the electoral roll in Southern Tasmania (population 229,000), with a response rate of 57%. Exclusion criteria included contraindication for magnetic resonance imaging and institutionalisation. Of the 1100 enrolled in the study, 1099 attended a

Results

Twenty outlier cases (9.5% of the sample, 10 Female) that had a standard score of 3 or greater were removed from the analyses. Another two cases (0.95% of the sample) were removed because of missing HVLT-R data, resulting in 188 participants being included in the analyses (see Table 1 for participant characteristics). The sample analysed differed little from the initial sample prior to exclusions (see Section 2). Examination of residuals scatter plots for TMT variables showed that the

Discussion

The utility of accelerometers to objectively measure PA behaviour distinguishes this study as one of the few that accurately quantifies the associations between cognitive functioning, muscle strength, and PA behaviour. In our cross-sectional analysis of older adults, older age and reduced cognitive functioning was negatively associated with psychomotor speed. However, there was no significant association between PA behaviour or muscle strength and psychomotor speed. Alternatively, when

Conclusion

This study found light PA is associated with higher levels of cognitive functioning in a sample of older adults. The significance of this finding should not be underestimated, as this is one of the few studies of its type to employ an objective measure of PA behaviours. Notwithstanding the existing evidence of the benefits of PA for cognitive functioning, our findings have important implications for the appropriate prescription of exercise to preserve older adult's executive functioning. For

Practical implications

  • Higher levels of light PA may help older adults to preserve their executive functioning.

  • A greater intensity of PA and increased sedentary time may not necessarily enhance cognitive functioning.

  • Elderly individuals who are deconditioned or new to exercise might benefit physically and cognitively from light PA.

Acknowledgements

The TASOAC study was supported by the National Health and Medical Research Council of Australia; Arthritis Foundation of Australia; Tasmanian Community Fund; University of Tasmania Institutional Research Grants Scheme. This analysis was supported by the Australian Government's Collaborative Research Networks program. We wish to thank the TASOAC staff and volunteers, in particular the study coordinator Catrina Boon, and we are appreciative of the time and efforts of all the TASOAC participants.

References (30)

  • E. Scherder et al.

    Executive functions of sedentary elderly may benefit from walking: a systematic review and meta-analysis

    Am J Geriatr Psychiatry

    (2014)
  • World Health Organisation

    A guide for population-based approaches to increasing levels of physical activity

    Implementation of the WHO global strategy on diet, physical activity, and health

    (2007)
  • D.H. Paterson et al.

    Physical activity and functional limitations in older adults: a systematic review related to Canada's physical activity guidelines

    Int J Behav Nutr Phys Act

    (2010)
  • C.H. Hillman et al.

    Be smart, exercise your heart: exercise effects on brain and cognition

    Nat Rev Neurosci

    (2008)
  • F. Sofi et al.

    Physical activity and risk of cognitive decline: a meta-analysis of prospective studies

    J Intern Med

    (2011)
  • P.A. Boyle et al.

    Association of muscle strength with the risk of Alzheimer disease and the rate of cognitive decline in community-dwelling older persons

    Arch Neurol

    (2009)
  • D.E. Barnes et al.

    A longitudinal study of cardiorespiratory fitness and cognitive function in healthy older adults

    J Am Geriatr Soc

    (2003)
  • R.J. Shephard

    Limits to the measurement of habitual physical activity by questionnaires

    Br J Sports Med

    (2003)
  • J. Wilbur et al.

    The relationship between physical activity and cognition in older Latinos

    J Gerontol B Psychol Sci Soc Sci

    (2012)
  • J. Kerr et al.

    Objectively measured physical activity is related to cognitive function in older adults

    J Am Geriatr Soc

    (2013)
  • P.K. Myint et al.

    Body fat percentage, body mass index and waist-hip-ratio as predictors of mortality and cardiovascular disease

    Heart

    (2014)
  • G.G. Giles et al.

    Dietary questionnaire for epidemiological studies (Version 2)

    (1996)
  • D. Scott et al.

    Prospective associations between ambulatory activity, body composition and muscle function in older adults

    Scand J Med Sci Sports

    (2011)
  • I. Sánchez-Cubillo et al.

    Construct validity of the trail making test: role of task switching, working memory, inhibition/interference control, and visuomotor abilities

    J Int Neuropsychol Soc

    (2009)
  • E. Strauss et al.

    A compendium of neuropsychological tests: administration, norms, and commentary

    (2006)
  • Cited by (0)

    View full text