Movement is one of the most powerful ways to reduce of risk cognitive decline. In fact, brisk walking was the first activity that was shown to increase the size of the hippocampus – the area of the brain critical for memory in older adult humans. In that study, participants who were randomised to walk briskly for 40 min three times per week saw an increase in the size of the hippocampus compared to a control group after a year. Participants started with the 10 minutes of walking, increased it by 5 minutes every week. In addition to walking, almost any exercise can improve brain health, and one of the ways it does that is through the production of brain-derived neurotrophic factor (BDNF). Exercise particularly helps improve the amount and quality of sleep we get, and decreases inflammation, both of are critical factors in long-term brain health.
Resistance training or weight training also improves brain health and cognitive function in several ways. Improving strength and muscle mass is associated with better function of brain white matter – the areas of the brain responsible for making fast connections between brain areas or between the brain and the body. Other studies have shown that loss of muscle mass is associated with lower brain volume and dementia, and muscle mass was also positively correlated with cognitive function in individuals from the UK biobank study. Only four sets per week of resistance training, which can be done in a few minutes, is enough to see benefit.
The final important area of movement and dementia risk is movements that involve coordination or balance. A recent meta-analysis suggested that exercise involving coordination are the best at improving cognitive function. For instance, one study showed that participants who did dance-based exercise saw greater improvements in the size of the hippocampus. You could even combine resistance and coordination movements by doing something like yoga or pilates.