The National Cancer Institute—a branch of the NIH—tracked the exercise habits and health outcomes of roughly 650,000 adults, most of whom were over the age of 40. Here’s what the researchers figured out: Those who completed 2.5 hours of moderate exercise every week—or half that amount of vigorous exercise—upped their life expectancy by up to 4.5 years.  Even tiny amounts of regular, moderate exercise—just 10 to 15 minutes daily—was enough to extend a person’s life by a year or more, according to study author Steven Moore, PhD, a member of the NCI’s Division of Cancer Epidemiology and Genetics. He says the benefits were even greater for people who are obese and anyone recovering from cancer or heart disease.  More from Prevention: 100 Little Ways To Lose Weight   What type of exercise do health scientists consider moderate? Walking at a pace of two steps per second fits the bill, finds a study published in Preventative Medicine. The NIH also offers this rule of thumb: While you work out, if you can talk but can’t sing, then that’s moderate exercise. If you could only say a few words without losing your breath, you’re exercising vigorously.  Looking for a few unconventional ways to meet your weekly workout quota? The CDC and the Mayo Clinic say these activities meet the criteria for “moderate" exercise: Mowing the lawn, dancing, swimming, gardening, shoveling snow, playing with children, raking and bagging leaves, or house chores like cleaning dishes or vacuuming. Basically, anything that would cause you to breathe quickly or break a sweat within 10 minutes will get the job done. More from Prevention: The Habit That Can Save Your Life