Recent study revealed that exercise can affect hippocampus size and memory in humans. Earlier studies have already proven this phenomenon in animal models. A curved structure deep inside the brain is known as hippocampus. It is a key player in spatial navigation and other types of relational memory.

Research led by Art Kramer of the University of Illinois and Kirk Erickson of the University of Pittsburgh, analyzed data collected from 165 adults, ages 59 to 81.

Study subjects' hippocampus volume was measured. Then they were given a test of spatial memory. Researchers measured aerobic fitness by VO2 max.

Researchers found that higher fitness levels led to a larger hippocampus which improves spatial memory.

Kramer said: "The higher fit people have a bigger hippocampus, and the people that have more tissue in the hippocampus have a better spatial memory."