We know that walking is good for us - but how far should you walk every day to see the health benefits? A new study has suggested a link between how much walking we do and life expectancy, with the least physically active people predicted to benefit the most from a daily stroll.
Health experts have warned that not doing enough exercise can contribute to serious illnesses for years, but researchers at Griffith University have found that pulling on your walking shoes and getting out the door may have even more of a positive health impact than we first thought.
"If there's something you could do to more than halve your risk of death, physical activity is enormously powerful," says Dr Lennert Veerman, the study's lead author.
The study, published in the British Journal of Sports Medicine, examined the link between physical activity and life expectancy in those over 40. The researchers found that if the general population was as active as the top 25%, they could live five years longer. Provided the least active individuals walked for an additional 111 minutes every day at the same speed, they could live for an extra 11 years.
The researchers looked at the activity levels of over 36,000 American adults over the age of 40 through data on their fitness trackers, translating all types of moderate and vigorous exercise into walking minutes to make the data easier to interpret. This was combined with an analysis of U.S. Census data from 2019 and 2017 death data, to predict how different levels of physical activity influence life expectancy.
The researchers found the least active 25% of participants did an equivalent of 50 minutes of walking per day. That's movement throughout the day - not all at once. The second least-active group walked for about 80 minutes and the third least active for about 110 minutes. The most active 25% of participants logged an equivalent of 160 minutes - just over two and a half hours - of walking every day.
From this, the researchers predicted that if everyone over 40 was as active as the top 25%, life expectancy would increase by over five years from 78.6 to 84 years. However, being among the least active led to a reduction in life expectancy of almost six years, so researchers predicted that doing an extra 111 minutes of walking per day could lead to an additional 11 years of life expectancy for those in this group.
How far should you walk every day?
The research showed that exercise was linked positively with life expectancy, so it makes sense that the more you walk, the better off you'll be. The 25% most active participants in the study walked for 160 minutes at 3mph - working out to 8 miles (12km) every day.
If everyone upped their steps to this amount, the researchers predict everyone could increase their life expectancy by five years - from 78.6 to 84.
To gain the predicted decade, the least active would need to walk an additional 111 minutes at 3mph, on top of the regular 50 minutes, working out to just past the 8-mile (or 12km) distance.
The more you walk, the more benefits of walking you gain. The study suggests that those at the lowest activity level are predicted to gain an extra 6.3 hours of life expectancy with every extra hour walked. So, even walking 30 minutes a day or getting outside for an early morning walk - alongside other exercise - can make a difference.
A note on this study
Though this is good news for those who like counting their steps on a fitness tracker - and answers the question of 'is walking enough exercise' - this study only looked at participants' activity over four days. This means their walking habits might not be reflective of what they'd do normally - though the researchers advised participants to continue as normal. As it's an observational study, researchers have warned against establishing cause and effect.
However, if someone did take up the challenge of walking more over those four days, they'd likely be more active than the average person in their daily life anyway.
This also isn't the first study to connect walking to a longer life expectancy. Studies linked to Tohoku University Graduate School of Medicine and University Medical Center Rotterdam got there first, to name just two in the last couple of years, and this new research does further contribute to the point that exercise can help boost longevity, offering a tangible (and achievable, for many people) goal to work towards.
