Minutes of exercise a day may add years to your life

Want to increase your life expectancy? Forget making a deal with the devil. You are, however, going to have to get off the couch.

Scientists have discovered that people who engage in physical activity for even a few minutes a day are likely to live months, even years, longer than those who are sedentary. Even if people are overweight, they are more likely to live longer if they are physically active.

A study published in the journal Public Library of Science Medicine this week found the connection between physical activity and longer lifespans.

The study's researchers, based in Sweden and the United States, examined the body mass index and leisure time activities of more than 650,000 people over age 40. They found that people who engage in relatively short amounts of physical activity – up to 75 minutes of brisk walking a week, for instance – lived 1.8 years longer, on average, than individuals who were physically inactive.

The benefits don't stop there. People who got a minimum of 150 minutes of physical activity a week, the amount recommended for Canadian adults, increased their life expectancy by 3.4 to 4.5 years compared with those who weren't physically active.

It's been known for years that physical activity, which ranges in intensity from walking to cycling to marathon running, can help prevent cancer, heart disease and other serious conditions. But this study provides proof that the benefits of physical activity can be measured in years of longer life. Being physically active may also help ensure that a person will be able to maintain good health and independence as they age.

"This finding may help convince currently inactive persons that a modest physical activity program is 'worth it' for health benefits, even if it may not result in weight control," the authors stated in a news release. No matter their weight, people who were physically active had a longer life expectancy, on average, than those who were sedentary. One of the most striking findings that backs up the importance of physical activity? The researchers found the life expectancy of people who have a "normal" BMI but are physically inactive is 3.1 years less than people who are obese but active.

The authors pointed out that "even low amounts of leisure time physical activity" may lead to a longer lifespan.

The life expectancy benefits of physical activity appear to plateau at about 300 minutes of brisk walking a week, the authors said.