The Impact of Exercise on Cognitive Brain Health in Older Adults
Overview of Clinical Trials
Nearly 1,000 clinical trials have investigated the effects of physical exercise on cognitive brain health among older adults. The majority of these studies indicate a positive relationship between exercise and cognitive function. However, the specific amount of exercise required to achieve these cognitive benefits remains unclear.
Research Methodology
A global team of researchers aimed to address this gap by systematically reviewing randomized controlled trials that assessed the impact of exercise on brain function in older adults. Randomized controlled trials are considered the gold standard in clinical research, wherein participants are randomly assigned to either an exercise group or a non-exercising control group.
To evaluate brain function, researchers tested participants at both the beginning and the end of the studies, measuring factors such as memory, processing speed, and visuospatial awareness. They then compared improvements in brain function between the exercise group and the control group.
Findings from the Review
The results of this comprehensive review were published in “Neurology: Clinical Practice,” the official journal of the American Academy of Neurology. The researchers identified 98 randomized controlled trials involving over 11,000 participants aged 60 and older. These studies included individuals with normal cognitive function, mild cognitive impairment, and various forms of dementia, including Alzheimer’s disease. Notably, two-thirds of the studies focused on aerobic exercise or a combination of aerobic and resistance training.
Exercise Duration and Brain Health
The analysis revealed that improved brain health was linked to the total amount of time spent exercising, rather than the frequency of exercise sessions, session duration, intensity, or overall study duration. Participants in studies that observed cognitive improvements engaged in an average of 52 hours of exercise, compared to only 34 hours in studies that did not report improvements.
Despite this finding, the frequency and duration of individual sessions were still relevant. The average study involved approximately three exercise sessions per week, each lasting about one hour. This aligns with current recommendations from the US Department of Health and Human Services and the American Heart Association, which advocate for 150 minutes of moderate exercise weekly. The study suggests maintaining this exercise schedule over a significant period is essential for enhancing brain health.
Implications for Older Adults
The researchers highlighted several limitations in their analysis. Most participants had no prior exercise experience before starting their programs, leaving it uncertain whether those already active would continue to see cognitive improvements. Additionally, the cognitive assessments used might be overly sensitive, potentially detecting minor improvements that do not translate into meaningful changes for the participants’ daily lives.
Future research is needed to explore these questions further. Nonetheless, the researchers concluded that there is substantial evidence supporting the notion that exercise can enhance cognitive brain health in older adults. Specifically, engaging in at least 52 hours of exercise, divided into approximately one-hour sessions, was associated with better cognitive performance.
Reference
Gomes-Osman, J., Cabral, D. F., Morris, T. P., McInerney, K., Cahalin, L. P., Rundek, T., Oliveira, A. & Pascual-Leone, A. Exercise for cognitive brain health in aging. Neurology: Clinical Practice 8, 257-265 (2018).