Physical Activity`

Incremental physical activity (PA), even of light intensity, is associate with larger brain volume and healthy brain aging, according to a study published online April 19 in JAMA Network Open. However, further work is need to pinpoint the optimal dosage (duration × intensity) of PA need to promote healthy brain aging.

Favorable brain structure

Although this question cannot be fully address in an observational study, our investigation sheds light on the dosage of PA most strongly associate with favorable brain structure in a community setting. Total PA (steps per day), MVPA, light-intensity PA, and sedentary time measure using an Actical accelerometer.
The devices were worn on a belt attach to the hip for 8 days, but at least 3 days of data were require for inclusion in our analyses. Participants in the third-generation cohort were instruct to wear the accelerometer 24 hours per day. They encounter difficulty distinguishing between sedentary and sleep time; hence, at the later offspring cohort examination cycle, they instruct participants to wear the accelerometer during waking hours only.
All participants were instruct to remove the device for bathing or swimming. Using data from the Framingham Heart Study, Nicole L. Spartano, Ph.D., of the Boston University School of Medicine, and colleagues conduct a cross-sectional, community-based cohort study of the association of accelerometry determine PA with brain magnetic resonance imaging (MRI) measures in a sample of 2,354 participants.

Total steps walk per day

The authors sought to examine the association of total steps; so walk per day and total dose (intensity × duration) of PA with brain volumes on MRI. The researchers found that each additional hour spent in light-intensity; so physical activity was equivalent to approximately 1.1 years less brain aging.  For individuals not meeting the PA guidelines, each hour of light-intensity PA and walking 7,500 steps or more per day correlate with higher total brain volume; its equivalent to about 1.4 to 2.2 years less brain aging.

After adjusting for light-intensity PA, neither increasing moderate to vigorous PA levels; nor meeting the threshold moderate to vigorous PA level recommend by the PA guidelines; hence were significantly associate with total brain volume, the authors write. These data are consistent with the notion that the potential benefits; hence of PA on brain aging may accrue at a lower, more achievable level of intensity or duration.

Hence the results from our study suggest that the threshold of the favorable association for PA with brain aging may be at a lower, more achievable level of intensity or volume. Our investigation is in agreement with the HHS 2018 PA guidelines, which suggest that some PA is better than none. These data will need to be replicate in other cohorts and be test in intervention trials.