Exercise can improve brain function and protect against dementia. It promotes increased blood flow to the brain which means more oxygen and nutrients in, and toxins out. However, there are still some questions about whether exercise will help older adults in this regard? What about those who already have some cognitive impairment, even early dementia? What sort of exercise, load and duration will be effective?
A group of exercise physiologists in Australia investigated over 10,000 randomized studies of exercise and brain function to test a specific hypothesis. After appropriate filtering they came down to 39 studies. They then took the data from all those studies and applied complex statistical analyses to evaluate:
- The types of exercise (cardio, resistance training like weights, both yoga or tai chi)
- The exercise intensity (low, medium, high)
- The duration, in minutes
- Frequency (how often) and length (1 to 3 months, 3 to 6 months, or over 6 months)
- Various brain functions (general cognition, attention, executive function, and memory)
People over 50 who performed any moderate cardio exercise regularly for at least 45 minutes, regardless of frequency or length, improved their cognitive functions, as did undertaking resistance training. One type of recommended training is tai chi, which improved memory. These results were seen regardless of baseline cognition, meaning even people with early dementia saw benefits.
Many types of exercise can improve memory, and people are encouraged to focus on developing specific exercise prescriptions tailored to improving specific cognitive functions. Further research is needed for activities well-suited for people with mobility issues, for example yoga and tai chi.