Doing 20 minutes a day of mild exercise (like walking, swimming or dancing) can help counter slight memory loss and improve your fluency. Recent research in people over 50 also suggests that the benefits of this small amount of daily exercise can last from 12 to 18 months and may even help those who are at risk for Alzheimers (those who exhibit mild cognitive decline). Being active not only improves blood flow to the brain, but it also relieves stress and enhances mood.