Walking is good for the heart, it helps keep blood pressure, cholesterol and blood sugar under control. Walking a lot not only improves your health but extends your life. And not by little. This is the picture outlined by a study conducted by scientists at the Griffith University School of Medicine and Dentistry in Gold Coast, Australia.
Many studies have examined the link between physical activity and longevity. The study coordinated by Professor Lennert Veerman, professor of Public Health at the Australian university, was inspired by research published in 2019 in the British Medical Journal which associated the decrease in the risk of premature death with the increase in physical activity monitored with trackers used by the subjects involved. “I asked myself how this would translate in terms of life expectancy and how much more time a single hour of walking could add,” said Veerman, interviewed in the past by CNN, to illustrate the goal of his work.
The study
To get to the finish line, the researchers used physical activity data tracked by sensors for at least 10 hours a day for four or more days. The monitoring covered adults aged 40 years and older who participated in the National Health and Nutrition Examination Survey (NHANES) between 2003 and 2006. The choice of age group is not random: mortality rates related to physical activity are stable up to age 40. From that threshold onwards, however, they vary.
Scientists have developed a ‘life table’, a method of showing the probability of a population reaching or dying by a certain age. The system is based on mortality data collected by the National Center for Health Statistics for 2017: the authors hypothesized that they were related to physical activity levels from 2003-2006.
Based on this information, the researchers estimated how many people in the 2019 US population would survive into subsequent years based on their physical activity levels and how many years they could gain with increased sport and exercise.
Results, conclusions and limitations
Result? They found that engaging in the level of physical activity of the least active portion of the population would result in a loss of 5.8 years of life expectancy for men and women: from about 78 to about 73 years. If all subjects over the age of 40 had the same level of physical activity as the most active group, life expectancy would instead be 83.7 years, with an increase of 5.3 years. The ‘laziest’ subjects simply walked for a total of 49 minutes at around 4.8 kilometers per hour per day. The levels of total physical activity in the intermediate performance groups carried out activities for 78 and 105. The most active overall, however, moved for 160 minutes a day: 2h40′ of total activity.
The team also examined the potential benefits at the individual level, rather than at the population level, finding that if the least active people dedicated 111 more minutes to physical activity every day – going from 49 to 160 minutes – they could extend their lives by up to 11 years: from almost -6 years they would go to +5 with a total reversal.
The study, according to other members of the scientific community, It has some limitations despite being considered useful and reliable. It is based on pre-existing data and provides largely theoretical estimates. The same authors noted that the activity levels of the participants in the 2003-2006 study were measured over a limited period and this does not allow changes over the course of life to be taken into account.
