Walk Your Way to a Longer Life
A new study shows a brisk walk increases life expectancy, even if you're overweight
--by Alexia Severson
Even if you don’t need to lose weight, regular exercise can help you live longer, according to a study by international researchers published in this week’s PLOS Medicine.
Researchers found that people who are physically active at a level equivalent to brisk walking for up to 75 minutes per week have an increased life expectancy of 1.8 years compared to those who do not exercise.
The World Health Organization recommends a minimum of 150 minutes of brisk walking per week, which according to researchers, could extend your life an average of 3.4 to 4.5 years. In contrast, less physical activity is associated with a shorter life expectancy at all body mass index levels. For example, being inactive but having a normal weight was associated with 3.1 fewer years of life compared to being active but obese.
According to the Centers for Disease Control and Prevention, “measurements of height and weight help to assess the overall health and nutritional status of adults.” Body Mass Index (BMI) can be calculated as weight in kilograms/height in meters squared. A healthy BMI value for the average woman is between 108 and 144, while the equivalent for a man is between 121 and 163.
The Expert Take
For this study, Steven Moore of the National Cancer Institute in Bethesda, MA and his colleagues used information on leisure time physical activity and BMI from more than 650,000 people in a combined analysis of six long-term studies, including one from Sweden and five from the U.S.
They determined that “physical activity above the minimal level—at recommended levels, or even higher—appears to increase longevity even further, with the increase in longevity starting to plateau at approximately 300 minutes of brisk walking per week.”
The team also found that while an overweight person who is physically active can increase his or her life expectancy, an obese person who is not physically active will have a significantly diminished life expectancy.
Source and Method
Researchers examined the association between leisure time physical activity and mortality during follow-up in pooled data from six prospective cohort studies in the National Cancer Institute Cohort Consortium, comprising 654,827 individuals between 21 and 90 years of age. Physical activity was categorized by metabolic equivalent hours per week.
Life expectancies and years of life gained or lost were calculated using direct adjusted survival curves. The study includes a median 10 years of follow-up and 82,465 deaths.
Researchers involved in the study said these findings could “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.”
This research also shows that staying fit doesn’t have to mean a trip to the gym to lift weights; something as simple as taking a brisk walk a few times a week can have long-lasting benefits.
This study is the first to estimate years of life lost based on both physical activity and BMI. However, many studies have examined the benefits of regular exercise for the quality and length of life. A study published online in The Lancet in 2011 showed that just 15 minutes of physical activity per day could reduce a person's risk of death by 14 percent and increase life expectancy by three years, compared with inactive people.
Similarly, research from the Copenhagen City Heart study presented at the EuroPRevent2012 meeting on May 3, in Dublin, Ireland, revealed that jogging increases the life expectancy of men by 6.2 years and of women by 5.6 years.
Healthy, older adults who regularly participate in physical activity of at least moderate intensity for more than one hour per week also have a higher health-related quality of life (HRQL), according to a study published online in Health and Quality of Life Outcomes in 2006.