Everybody wants six-pack abs and chiseled features, but the most important part of your body may be the one that gets the least exercise: your mind! What physical exercise does for your body, mental exercise does for you brain. Here are some easy ways to flex your most important muscles and boost your mental fitness.

Learn something new. Learning new skills like a musical instrument or a foreign language challenges your brain to grow. In fact, the more you learn, the faster your mind operates. But you don't have to jump in head first to see results, just reading or adopting a new hobby can reap serious rewards.

Relax. Continuous stress over long periods of time can cause your brain to release potentially damaging hormones. This kind of continuous stress can be dangerous for your mind, and your body. Periodic deep breaths and meditation can do wonders for helping to alleviate stress, keeping your mind (and body) sharp, and slowing down the aging process. 

Eat, drink and be merry. Antioxidants in fruits and vegetables can improve blood flow to your brain. Vitamin rich foods like oranges, spinach and berries can actually protect your brain cells. Fish, heavy with omega-3 fatty acids has also been shown to help boost brain activity, as does alcohol (in moderation, of course).

Be more than a fly on the wall. Social activity and networking can help stir up brain activity. Expert Lawrence Katz writes, "There's a lot of evidence that other people are the most unpredictable things you can encounter, so activities that have you engaging with other human beings are a fantastic form of brain exercise." 

Don't underestimate the importance of keeping your mind fresh, alert and in use. Minor changes in the way you live your life can make sure that you're around to live it (and enjoy it) for far longer.