Moderate physical activity in midlife, for instance a strenuous walk, is associated with better cognition in old age, finds a new research."The study suggests that the beneficial influence of physical activity on the brain and cognition is not solely based on decreasing vascular risk factors," said researcher Paula Iso-Markku from the University of Helsinki in Finland.The study was conducted in pairs where one twin was more physically active than the other and found that increasing the volume of physical activity was not associated with increased memory-protecting benefits.Instead, quite a moderate amount of physical activity was found to be sufficient for memory-protecting benefits and only the most inactive group of twins stood out with a significantly higher risk for cognitive impairment, suggested the study published in the Journal of Alzheimer's Disease. The traditional vascular risk factors (elevated blood pressure, hypercholesterolemia, obesity, diabetes and lack of exercise) have also been associated with dementia risk.Although the incidence of dementia seems to have decreased in less senior generations, the total prevalence of dementia is still expected to rise. "However, few long-term, high-quality, follow-up studies on physical activity and cognition have been published, and it has remained unclear what type and amount of exercise is needed to safeguard cognition," Iso-Markku added.