"In the broader of the two studies, researchers with the National Cancer Institute, Harvard University and other institutions gathered and pooled data about people’s exercise habits from six large, ongoing health surveys, winding up with information about more than 661,000 adults, most of them middle-aged.
They found that, unsurprisingly, the people who did not exercise at all were at the highest risk of early death.
But those who exercised a little, not meeting the recommendations but doing something, lowered their risk of premature death by 20 percent.
Those who met the guidelines precisely, completing 150 minutes per week of moderate exercise, enjoyed greater longevity benefits and 31 percent less risk of dying during the 14-year period compared with those who never exercised." - Gretchen Reynolds via The New York Times