You may have seen a lot of headlines in recent weeks touting the fact that people need to perform only 11 minutes of exercise each day to increase their lifespans. Sounds too good to be true, right? Which means it’s time to do a little digging to uncover the truth about the findings of the research being cited.
The research, which was published in the British Journal of Sports Medicine, has a title that would drive away many readers, so the desire to simplify things is understandable: “Joint associations of accelero-meter measured physical activity and sedentary time with all-cause mortality: A harmonized meta-analysis in more than 44000 middle-aged and older individuals.”
Stated simply, the researchers reviewed nine different studies, which together followed 44,370 men and women for 4.0 to 14.5 years, recording their time performing moderate-to-vigorous physical activity (MVPA) and their sedentary time, and then compared those values to their risk of death.
Overall, the participants averaged 8.5 to 10.5 hours/day being sedentary and 8 to 35 minutes/day performing MVPA. As you might expect, the risk of death increased as sedentary time increased and MVPA decreased. Based on their data analysis, the researchers concluded: “About 30–40 min of MVPA per day attenuate the association between sedentary time and risk of death.”
So, where did the 11 minutes mentioned in the headline come from?
The researchers broke the 44,000+ participants down into categories based on time spent sedentary and performing MVPA. The top group—what the researchers call the “referent group”—consisted of those individuals in the top third in terms of both MVPA and sedentary time. In other words, they exercised the most and were sedentary the least.
When comparing various groups to this referent group, they found that as little as 11 minutes per day of MVPA is needed to lower a person’s risk to that of the referent group, provided the individual was sedentary for fewer than 8.5 hours per day.
What this means is that, yes, 11 minutes of daily MVPA is enough to lower a person’s risk of death if they also find a way to limit their sedentary time. Given that so few of us are sedentary for less than 8.5 hours a day, those headlines screaming “11 minutes” are a little misleading.
The truth is, the more time spent being sedentary, the more MVPA a person needs to perform to counter the effects. It is also important to note that this research looked only at risk of death, not health, fitness, performance, wellness, quality of life or any of the countless other benefits of limiting sedentary time and being active. Living well should be the goal for most of us, not simply living.
This research offers a valuable lesson about reading headlines or catching snippets of news stories. When something sounds too good to be true, it often is. A deeper understanding of the science can help you analyze the research behind the headlines, and then be better able to explain it to inquisitive clients.