The evidence on the importance of being physically active for health and longevity is robust- that’s not in doubt; activity levels are often pitted against weight loss science to declare a winner on what is more impactful. The scientific reality is it all matters, just by different degrees, with weight loss strategies dominating in the early phases of weight management and increased activity levels being necessary for weight loss maintenance.
In the past fifteen years, many community development plans have incorporated “Active Living by Design” principles to encourage more people to get their 30 minutes a day of physical activity- the dose that support health. In this same timeframe, we have seen a rise in wearable technology that helps the wearer track activity levels, set goals, and in 2017, over 125 million wearables were shipped globally.
In the last decade, the mantra of 10,000 steps a day has permeated popular culture. If you have a wearable you are often applauded to reaching this milestone daily as you “walk your way” from San Francisco to Beijing- walking on water aside, it now seems that golden metric may have lost some of its cachets.
A new paper by I-Min Lee and colleagues from Harvard Medical School published in JAMA Internal Medicine looked at the association of step volume and intensity on all-cause mortality in older women. The author’s examined a prospective cohort of 18,289 women living in the USA. Activity levels were assessed by wearing an accelerometer 7-days a week during waking hours between 2011 and 2015. This study is an essential addition to our understanding of steps levels that impact health and mortality. A variety of step variables were calculated and included steps per day, peak 1-minute steps (number of steps recorded for a single highest minute of the day), Peak 30-minute cadence (mean steps for 30 highest minutes per day) as well as step cadence and rate.
The final analysis included data from 96% of study participants, which signals impressive compliance. Findings indicated 4400 steps a day was associated with a 41% reduction in mortality when compared to those with fewer steps (2700). Moreover, those achieving 7500 a day saw the highest decline in mortality levels, but rates peaked at this activity level. The authors also examined step volume and step intensity, again, the step amount seems to be a more significant contributor to declines in mortality rates.
The good news is this new evidence points a more transparent bar to meet to support longevity- a bar that more within reach than 10,000 steps a day. This does not mean that activity levels throughout the lifespan aren’t significant- this study had no way to control for the activity levels of the prior six decades of activity which are also building blocks for health. It is never too late to start being more active, which is an essential counter-narrative to aging that often translates to endings rather than transitions to new things.
Thanks for reading – Trina
(Opinions are my own)
Active Living By Design