NEW: Joint associations of accelerometer-measured physical activity and sedentary time with all-cause mortality: a harmonized meta-analysis in more than 44,000 middle-aged and older individuals

https://bjsm.bmj.com/content/54/24/1499

http://dx.doi.org/10.1136/bjsports-2020-103270


Correspondence to Professor Ulf Ekelund, Department of Sport Medicine, Norwegian School of Sport Sciences, Oslo 0806, Norway; Ulf.Ekelund@nih.no


PURPOSE:

To examine the joint associations of accelerometer-measured physical activity and sedentary time with all-cause mortality.


An accelerometer is a device that measures the vibration, or acceleration of motion of a structure.


PROCEDURES:

A harmonized meta-analysis was conducted including nine prospective cohort studies from four countries. 44,370 men and women were followed for four to 14.5 years during which 3,451 participants died (7.8% mortality rate).


Associations between different combinations of moderate-to-vigorous intensity physical activity (MVPA) and sedentary time were analyzed at study level and summarized using random effects meta-analysis.


CONCLUSIONS:

Moderate-to-vigorous-intensity physical activity and sedentary time as measured by accelerometry can be combined differently to reduce the risk of premature death.


Higher sedentary time is associated with higher mortality in less active individuals when measured by accelerometry.


Compared with the referent group (highest physical activity/lowest sedentary time), the risk of death increased with lower levels of MVPA and greater amounts of sedentary time.

About 30–40 min of MVPA per day attenuate the association between sedentary time and risk of death, which is lower than previous estimates from self-reported data. http://creativecommons.org/licenses/by-nc/4.0/


Those with as little as 11 min per day of MVPA in combination with ‘low’ sedentary time (<8.5 hours per day) did not differ in risk compared with the referent group (highest third of MVPA in combination with lowest third for sedentary time).


Compared to the lowest third of MVPA comprising those who accumulated about 2 min of MVPA per day on average, all combinations with sedentary time (8.5–10.7 hours per day) were associated with a higher risk of premature death.


IN PLAIN ENGLISH:

To increase one’s longevity – thus avoiding the “Big Nap” - performing moderate to vigorous exercise such as high intensity strength training or interval training can be performed in as little as 11 minutes per day, but preferably 30 to 40 minutes. On that, if those activities are only performed two or three days/week for a minimal amount of time, it is better than zero activity in adherence to the “doing something demanding, briefly, and infrequently is 100% better than doing absolutely nothing” principle.