Summary: Frequent moderate to vigorous exercise is linked to better cognition and brain power in middle age. This level of intensity was associated with better working memory and better mental processes. Reducing intensity to lower intensity or sedentary behavior for 6–7 minutes per day was associated with poorer cognitive performance.
According to research published online in the Journal of Epidemiology and Community Health.
This level of intensity appears to be best for working memory and mental processes, such as planning and organizing, and replacing it with just 6-7 minutes of light-intensity activity or sedentary behavior each day is associated with poorer cognitive performance, the results indicate.
Previously published studies link daily moderate and vigorous physical activity, or MVPA for short, to health, but few have included time spent sleeping, which makes up the largest portion of any 24-hour period, according to Researchers.
They therefore took a compositional approach to determine whether MVPA over all other everyday movement behaviors might be best for midlife cognitive performance.
They relied on participants from the 1970 UK Cohort Study, including people born in England, Scotland and Wales in 1970 whose health was tracked through childhood and later life. adulthood.
In 2016-2018, 8,581 participants had reached the age of 46 to 47, by which time they were asked to complete detailed health, background and lifestyle questionnaires, and to wear an activity tracker. up to 7 days and for at least 10 consecutive hours per day.
They took various cognitive tests for verbal memory (immediate and delayed word recall tasks) and executive function (verbal fluency and processing speed/accuracy).
Scores from each test were added together to produce an overall global score for memory and executive function.
Of those who agreed to wear an activity tracker, 2959 participants were excluded due to device error, insufficient wearing time, or failure to fully complete the questionnaires.
The final analysis included 4481 participants, of whom just over half (52%) were women. Two-thirds (66%) were married and 43% had studied until the age of 18. More than two-thirds (68%) were occasional or non-high-risk drinkers and half had never smoked.
Analysis of activity tracking data showed that participants logged an average of 51 minutes of MVPA, 5 hours 42 minutes of light-intensity physical activity, 9 hours 16 minutes of sedentary behaviors, and 8 hours 11 minutes of sleep over a 24-hour period.
Time spent in MVPA relative to other types of behavior was positively associated with cognitive performance after adjusting for level of education and physical activity at work. But further adjustment for health problems weakened these associations.
Sedentary behavior in relation to sleep and light physical activity was also positively associated with cognitive performance: a trend that likely reflects greater engagement in cognitively stimulating activities such as reading or working rather than any apparent benefit. to watch television, the researchers note.
The associations were stronger for executive function than for memory.
Compared to the sample mean, participants in the top half of cognitive performance scores spent more time in MVPAs and sedentary behaviors and less time sleeping, while the bottom 25% of scores recorded the lightest physical activity.
To better understand the joint associations of movement with cognition, the researchers reallocated time from one component to another, minute by minute, to estimate the impact this might have on overall cognitive performance scores.
This revealed increases in scores after MVPA theoretically replaced other activities.
The cognition of the individuals showed a 1.31% improvement in cognitive ranking compared to the average improvement of the sample after as little as 9 minutes of sedentary activities with more vigorous activities – a positive trend that has become much more substantial with much greater reductions in sedentary activities.
Similarly, there was a 1.27% improvement by replacing light activities or 1.2% by replacing 7 minutes of sleep. Such improvements showed further improvement with greater time trades.
Sedentary behavior also favored the cognitive score, but only after replacing it with 37 minutes of light-intensity physical activity or 56 minutes of sleep.
Participants theoretically began to decrease their cognitive ranking within the study sample by 1-2% after just 8 minutes of more vigorous activity being replaced by sedentary activities. The rankings continued to decline with larger drops in MVPAs.
Similarly, replacing vigorous activity with 6 minutes of light-intensity physical activity or 7 minutes of sleep was linked to similar 1-2% drops in cognitive ranking, again worsening for greater losses. important MVPA.
Activity trackers can only capture time spent in bed rather than sleep duration or quality, which could help explain the association with sleep, the researchers say.
“MVPA is generally the smallest proportion of the day in real terms and the hardest intensity to acquire. Perhaps this is partly why losing any MVPA time appeared detrimental, even within this relatively active cohort,” they explain.
This is an observational study, and as such cannot establish cause. And the researchers point out various caveats: Activity tracking metrics can’t provide context for every component of movement. And despite a large sample size, people of color were underrepresented, limiting the generalizability of the findings.
Nevertheless, they conclude, “This robust method supports the essential role of MVPA in supporting cognition, and efforts should be made to strengthen this component of daily movements.”
About this exercise, current research on aging and cognition
Author: Press office
Contact: Press office – BMJ
Picture: Image is in public domain
Original research: Free access.
“Exploring associations between everyday movement behaviors and mid-life cognition: a compositional analysis of the 1970 UK cohort study” by John J Mitchell et al. Journal of Epidemiology and Community Health
Exploring Associations Between Everyday Movement Behaviors and Midlife Cognition: A Compositional Analysis of the 1970 UK Cohort Study
Movement behaviors (eg, sedentary behavior (SB), moderate-vigorous physical activity (MVPA), light-intensity physical activity (LIPA), and sleep) are related to cognition, but the relative importance of each component is unclear and has not yet been explored with compositional methodologies.
To (i) assess the associations of different components of daily movement and the participant’s global cognition, memory, and executive function, and (ii) understand the relative importance of each individual component for cognition.
The British Cohort Study 1970 (BCS70) is a prospective birth cohort study of adults born in the United Kingdom. At age 46, participants consented to wear an accelerometer and take tests of verbal memory and executive function. Compositional linear regression was used to examine cross-sectional associations between 24-hour movement behaviors and standardized cognition scores. An isotemporal substitution was performed to model the effect of time reallocation between daily movement components on cognition.
The sample included 4481 participants (52% women). Time spent in MVPA relative to SB, LIPA, and sleep was positively associated with cognition after adjustments for education and occupational physical activity, but additional adjustment for health status attenuated the associations. SB versus all other movements was strongly positively associated with cognition. Reallocation of modeling time between components revealed an increase in cognitive percentile after MVPA theoretically replaced 9 min of SB (OR = 1.31; 95% CI 0.09 to 2.50), 7 min of LIPA (1.27; 0.07 to 2.46) or 7 min of sleep (1.20; 0.01 to 2.39).
Compared to time spent in other behaviors, greater MVPA and SB were associated with higher cognitive scores. The MVPA time loss, given its smaller relative amount, seems the most deleterious. Efforts should be made to preserve MVPA time or reinforce it in place of other behaviors.