Exercise gets the blood flowing. That helps your brain get the oxygen and nutrients it needs for top performance. Some research found that people who rode a stationary bike or walked on a treadmill for 30-60 minutes, three times a week, had improved blood flow to the area of the brain that deals with memory retention. After 12 weeks, they did better on memory tests. Other types of exercise can be helpful as well. Yoga three times a week has been found to improve brain function in older adults.