Life expectancy is
defined as the statistically 'expected number of years of life remaining at a
given age'. Physical activity is believed to enhance life expectancy.
Steven Moore and
colleagues, from USA, studied the effect of leisure time physical activity on
life expectancy. They also enumerated the number of years acquired by being
energetic and physically active at different levels of life among people with
different body mass indices (BMI).
I-Min Lee, MD, the
Associate Epidemiologist in the Department of Preventive Medicine at BWH and
senior author on this study said, "We found that adding low amounts of physical
activity to one's daily routine, such as 75 minutes of brisk walking per week,
was associated with increased longevity: a gain of 1.8 years of life expectancy
after age 40, compared with doing no such activity,"
Prof. Lee further
added, "Physical activity above this minimal level was associated with
additional gains in longevity. For example, walking briskly for at least 450
minutes a week was associated with a gain of 4.5 years. Further, physical
activity was associated with greater longevity among persons in all BMI groups:
normal weight, overweight, and obese."
Since the size of the
sample was quite large, it was possible to determine the number of years gained
at various levels of BMI and physical activity.
The study findings
suggested that increased physical activity was closely linked with increase in
life expectancy. The scientists found that by involving themselves in leisure
time physical activity, people enhanced their life expectancy by 4.5 years.
It was also seen that
volunteers who were active and had normal weight gained 7.2 years of life as
compared with their non-active counterparts.
The data was gathered
from six prospective cohort studies in the National Cancer Institute Cohort
Consortium, consisting of 654,827 volunteers aged between 21 to 90 years.
Dr. Steven Moore from
the Division of Cancer Epidemiology and Genetics, National Cancer Institute,
Bethesda, Maryland and the lead researcher of this study said, "Our
findings reinforce prevailing public health messages promoting both a
physically active lifestyle and a normal body weight."
scientists moderate activities are those activities during which a person can
talk but cannot sing while vigorous activities are the activities can utter
only few words without taking a short breath.
Various other factors
such as socioeconomic status, nutritional status, etc. affect life expectancy.
The researchers observed that the life expectancy of those who followed a
recommended level of physical exercise was increased by 3.4 years while those
who followed twice the recommended exercise level increased their life
expectancy by 4.2 years.
The scientist said
that even the low level of physical activity also resulted in enhancing the
life expectancy by 1.8 years.
Dr. Moore mentioned,
"Our findings highlight the important contribution that leisure-time physical
activity in adulthood can make to longevity."
He added, "Regular
exercise extended the lives in every group that we examined in our study—normal
weight, overweight, or obese."
The researchers found
that, the relation between life expectancy and physical activity was almost
identical in both women and men; but blacks gained more number of years as
compared to whites.
point highlighted by the scientists was that people with a prior history of
heart ailment had stronger relationship between physical activity and life
expectancy, as compared to those people who did not have any such history.
The study concluded that increased level of leisure physical
activity was responsible for longer expectancy of life in different BMI groups.
Leisure Time Physical Activity of Moderate to
Vigorous Intensity and Mortality: A Large Pooled Cohort Analysis; Steven Moore
et al; PLOS Medicine 2012