A recent trip up north took me to a quaint, seaside town in Maine. There, I enjoyed some great hikes, some nice long walks, and the benefit of crisp, fresh air. But, I also enjoyed waaaaaay to many calories at the dozens of ice cream shops that lined the streets. As a kid, I could have eaten these treats with relative impunity. These days, however, these temporary lapses in my fitness judgment can only be afforded if they remain just that: temporary.

It's a natural -- though very unfortunate -- fact that our metabolism tends to slow down somewhere around the age of 25. From there, it slows down by around five to ten percent with each subsequent decade that passes. Does this mean that you're fate is sealed and that you must accept your overweight destiny? Not at all.

By exercising regularly, you can keep your metabolism decline under a great deal of control. For the most part, if you get up and start moving every day you can very well increase your metabolism, or at least keep it to around a 0.3 percent drop, per decade.