As if you really needed it, here's another reason to get more exercise: it improves your memory. That's the finding of a study recently conducted by scientists at Canada's McMaster University. And although the research involved healthy young adults, it could have big implications for older people.

In the study, 95 test subjects were split into three groups for a period of six weeks.

During that time, one group underwent intensive daily exercise training, one group did both exercise and cognitive training, and one group did neither. When they were tested afterwards, members of the first two groups showed improved performance on a memory task, while members of the third group did not.

Tellingly, it was additionally found that test subjects who experienced the largest gains in physical fitness also had the greatest increases in brain-derived neurotrophic factor (BDNF), which is a protein that supports the growth, function and survival of brain cells.

Led by assistant professor Jennifer Heisz, the research team is now beginning to look at how exercise affects memory in elderly test subjects. While the results may be even more pronounced, due to the memory loss that occurs with old age, it's also possible that the memory-boosting effect of exercise will be muted by the decreased availability of BDNF, which also declines with age.