Photo: Rob Inh00d, Flickr

In this hectic world, there's nothing better than taking care of two things at one time. Physical exercise will reward you with greater energy, overall health and a fit body -- but did you know that exercise also helps you develop a fit mind? It's true! When you work out your body, you also work out your mind.

In addition to cognitive challenges (such as taking a class, learning a new skill or even just doing some brain teasers), several studies concur that physical activity helps keep your mind sharp. Moderate activity has a positive impact on mental acuity, but cardio workouts that really get your heart pumping seem to have the greatest effect. What's more, an active lifestyle will have a long-lasting impact on your mental fitness.

The mind and the body are closely connected. One study found that even short bouts of physical activity in previously-sedentary seniors restored some of the brain loss that's associated with aging.

Exercise is also a great stress reliever. As you're running or biking (or whatever else gets your heart pumping), you'll have time to sort through your thoughts and process your emotions. If you want to really give your brain a good workout, look for a new sport to try or set up a challenging obstacle course -- the combination of physical and mental stimulation will do you good.