If you're thinking, "I've been inactive for so long, what good will exercise do me now?" The answer is: a lot! It is never too late to get in shape. And even if you have been inactive for decades, making a change this year can dramatically improve your health and quality of life in your later years.

In fact, German researchers recently revealed that people who were inactive between the ages of 20 and 39 but started exercising at 40 cut their chances of developing heart disease by 55 percent. Those who started at 40 and remained active fared better than those who were active in their younger days but took to the couch after 40. And, not surprisingly, the benefit was greatest for those who became "very active."