Exercise may be an effective intervention for improving brain function in older adults

September 13, 2021

Author: Nick Bray

Ph.D., CSEP-CEP
Department of Kinesiology, Western University, London, Ontario, Canada

Background

  • Many studies provide evidence of exercise improving cognitive outcomes; however, the physiological mechanisms that lead to such changes remain undetermined.
  • Functional brain network connectivity (FBNC) refers to brain areas that are anatomically separate but linked in their neural activity; it enables the completion of complex cognitive functions and information processing.
  • FBNC is a sensitive biomarker as changes precede structural brain atrophy and occur years before clinical manifestation (e.g., memory loss).

How the study was done

  • The purpose of this pre-registered systematic review was to:
    • assess the effect of exercise with and without other interventions on FBNC in older adults that were cognitively healthy and impaired.
    • evaluate the impact of exercise interventions on physical and cognitive function.
    • review the relationship between FBNC and physical and cognitive function in older adults.
  • A literature search, without date or language restrictions, yielded 1474 articles; after screening, we included 13 articles.
  • Eight studies focused on cognitively healthy older adults, including 480 participants ranging in mean age from 60 to 73 years and sample sizes ranging from 11 to 53 participants per group.
  • Five studies focused on older adults with cognitive impairments, including 203 participants ranging in mean age from 64 to 75 years and sample sizes ranging from 5 to 22 participants per group.
  • Aerobic exercise was the most common intervention with durations ranging from 6-weeks to 1-year and including 60 to 300-minutes of exercise per week.

What researchers found

  • Intervention groups increased FBNC in 10 out of 12 studies, which may reflect improved brain function.
  • Conversely, control groups primarily showed no change in brain function over the same period.
  • Exercise interventions improved various cognitive and physical performance outcomes, while control groups showed no change or declined over the same period.
  • Only one study demonstrated a relationship between changes in FBNC and physical and cognitive function.

Conclusion

  • Exercise increases within-network FBNC, but implications for behavioural (i.e., cognitive and physical function) outcomes remain unclear.
  • Lack of specific findings is due to high inter-study variability in exercise parameters, brain networks examined, and methodological approaches.

Take home message

  • Exercise may be an effective intervention for improving brain function in older adults
  • Potentially, exercise may delay neurodegenerative consequences of biological aging and Alzheimer’s disease.

Original Article: Bray NW, Pieruccini-Faria F, Bartha R, Doherty TJ, Nagamatsu LS, Montero-Odasso M. The effect of physical exercise on functional brain network connectivity in older adults with and without cognitive impairment. A systematic review. Mech Ageing Dev. 2021 Apr 19;196:111493. https://doi.org/10.1016/j.mad.2021.111493.

If you cite any information from this, please consult the original article and cite that source. This summary was written for the Canadian Society for Exercise Physiology and it has been reviewed by the CSEP Knowledge Translation Committee.