Neuropsychiatrist Kristine Yaffe and her colleagues assessed the physical activity of 5,925 women and gave them a questionnaire to fill out about their levels of participation in 33 different physical activities. After six to eight years, the researchers assessed the women’s level of cognitive function. The most active women had a 30 percent lower risk of cognitive decline, thus showing that even moderate levels of physical activity can serve to limit declines in cognition.