Looking to lose inches around your waist while adding years to your life? Then you may want to start by taking a short, brisk walk each day, according to a new study published in PLOS Medicine.

We all know that exercise is good for us. Physical activity keeps muscles and joints strong, helps with weight maintenance, relieves stress and elevates mood. Engaging in regular exercise also reduces the risk of certain diseases including some cancers.

“Compared to no leisure-time physical activity, participants with low levels of leisure-time physical activity had a 19% lower chance of dying and extended their lifespan by 1.8 years.”

What is less clear is to what extent regular physical exercise extends how long we live. And, this is exactly what a team of researchers led by the National Cancer Institute tried to answer in the current study. What they found is that more leisure-time physical activity in adulthood was associated with longer life expectancy across a range of activity levels and BMI groups.

Using data pooled from six studies that were designed to evaluate various aspects of cancer risk, researchers examined data on more than 650,000 adults. Leisure-time physical activity along with demographic and lifestyle measures were reviewed.

The median age of participants was 61 years and they were followed for an average of 10 years. During this time, about 82,000 deaths were recorded. Based on the large sample size, researchers were able to calculate the risk of death and years of life gained after age 40 based on leisure-time physical activity levels.

Compared to no leisure-time physical activity, participants with low levels of leisure-time physical activity had a 19% lower chance of dying and extended their lifespan by 1.8 years. This activity level was equivalent to brisk walking for up to 75 minutes per week (1.25 hours)!

At levels of activity two to three times above the minimum level recommended by federal guidelines†, participants lowered their risk of death by 39% and extended their lifespan by 4.2 years. The greatest gains in life expectancy occurred at about 300 minutes a week or a little over an hour a day of physical activity.

“Regular exercise extended the lives in every group that we examined in our study – normal weight, overweight or obese,” said lead study author Steven Moore, Ph.D.

Greater gains were also seen in some sub-groups. At the highest levels of activity, black individuals saw a gain in life expectancy of 6.4 years versus 4.5 years for whites. In former smokers, the gain was 5.5 years compared with 3.3 years for never smokers.

A lack of leisure-time activity combined with obesity was associated with markedly diminished life expectancy. For normal weight, inactive participants, the number of years lost were 4.7 years. But, for obese participants (BMI 35+), life expectancy was shortened by 7.2 years.

“We must not underestimate how important physical activity is for health - even modest amounts can add years to our life,” said I-Min Lee, M.D., professor of Medicine, Harvard Medical School and senior author on the study.

The Bottom Line

Even at low levels of activity, leisure-time physical activity is associated with longer life expectancy. Yet, only one third of adults engage in regular leisure-time physical activity. And, fewer than 50% of adults meet the 2008 guidelines for aerobic activity.†

In this study, participants with the highest levels of leisure-time physical activity were more likely to be male, non-smokers, college-educated and not obese. This supports government data that shows women's participation in leisure-time physical activity is lower than men's and this gap increases with age.

If you’re not currently physically active, the good news is that just by getting out and doing a brisk 10-minute walk a day, you can extend not only your healthspan but your lifespan. Anything you do above and beyond that level, will just pay greater health dividends.

Not sure where to start? The CDC has a great guide which outlines how to get started, making physical activity part of your life, keeping it up and being active for life.

†In the 2008 Physical Activity Guidelines for Americans, government health officials recommend that adults obtain one of following:

2 hours and 30 minutes (150 minutes) of moderate-intensity aerobic activity every week (e.g., walking fast, riding a bike on level ground or with few hills, playing doubles tennis, pushing a lawn mower) and muscle strengthening activities on 2 or more days of the week.

1 hour and 15 minutes (75 minutes) of vigorous-intensity aerobic activity every week (e.g., running, swimming laps, riding a bike fast or on hills, playing singles tennis, playing basketball) and muscle strengthening activities on 2 or more days of the week.

††Metabolic Equivalent of Task (MET) or Metabolic Equivalent

One MET is defined as the ratio of metabolic rate (the rate of energy consumption) during a specific physical activity to a reference rate of metabolic rate at rest. MET values of physical activities range from 0.9 (sleeping) to 18 (running at 10 miles p/hour).

• – 3.74 MET hours/week = brisk walk 0- 74 minutes week or 1.2 hrs (10.5 mins day)

3.75 – 7.4 MET hours/week = brisk walk 75 - 149 minutes week or 2.5 hrs (21.3 mins day)

7.5 – 14.9 MET hours/week = brisk walk 150 - 299 minutes week or 5 hrs (42.7 mins day)

15.0 -22.4 MET hours/week = brisk walk 300-449 minutes week or 7.5 hrs (64 mins day)

22.5+ MET hours/week = brisk walk 450+ minutes week or +7.5 hrs (64+ mins day)