Summary: Passive exercise increases cerebral blood flow and improves executive function, as well as providing the same cognitive benefits as active exercise.
A source: University of Western Ontario
Passive exercise increases cerebral blood flow and improves executive function, and provides the same cognitive benefits as active exercise, according to a new study by Western kinesiology graduate students.
Published Psychophysiologythe study is the first to look at whether there are benefits to brain health during passive exercise in which a person’s legs are propelled by an external force—in this case, bicycle pedals propelled by a mechanically controlled flywheel.
During a 20-minute session with healthy young adults, the team assessed executive function at baseline before the participants exercised and compared the data after the exercise. They found improvements in executive function of equal magnitude during passive and active exercise conditions, without increases in heart rate or diastolic blood pressure.
Executive function is a higher-order cognitive ability that enables people to make plans and supports activities of daily living. People with mild cognitive impairment, such as those experiencing early-stage Alzheimer’s symptoms, may experience a negative impact on their executive function.
Previous research has shown that vigorous exercise, in which a person activates voluntary muscles, increases blood flow to the brain and improves executive function. Passive exercise also increases blood flow to the brain, but this is much less well documented.
“In terms of passive exercise, we can predict the outcome because this kind of research hasn’t been done before,” said Matthew Heath, professor of kinesiology and lead author of the study.
During passive training, a person’s limbs are moving and muscle receptors are being stretched. This information is sent to the brain, indicating that the motor areas of the body and the connected areas of the brain need more blood. This increase in cerebral blood flow led to a similar magnitude of improvement in executive function, although it was much smaller than active exercise—an interesting finding for the researchers.
“The potential impact for people who are limited or immobile can be profound. “If done regularly, the increased blood flow to the brain and the resulting improvement in executive function will, optimistically, translate into a compounding effect that has significant effects on cognitive health and executive function,” Heath explained.
Further research could be improved by including more diverse participants (e.g., elderly or impaired) to determine whether the benefits of executive function persist over longer periods of time post-exercise.
Heath and team see great potential in using passive exercise in long-term care homes or in rehabilitation programs for people with musculoskeletal injuries who are unable to bear weight.
The study was led by graduate student Mustafa Shirzad and co-authored by graduate students Benjamin Tarr, Connor Dalton, James Van Riesen, and Michael Marsala. Heath was a corresponding writer.
This is about exercise and brain health research news
Author: Kim McCready
A source: University of Western Ontario
The connection: Kim McCready – University of Western Ontario
Photo: Photo courtesy of University of Western Ontario
Original research: Closed access.
“Passive Exercise Increases Cerebral Blood Flow and Supports Post-Exercise Executive Function Benefits” by Mustafa Shirzad et al. Psychophysiology
Passive exercise increases cerebral blood flow and supports post-exercise executive function.
Executive function requires a high level of cognitive control that supports activities of daily living. The literature suggests that a single bout of exercise with voluntary muscle activation (i.e., vigorous exercise) improves executive function, and that increased cerebral blood flow (CBF) may contribute to this benefit.
However, it is not known whether non-voluntary exercise (ie, passive exercise) in which a person moves their limbs with the help of an external force has the same effect on executive function. This is an important question given that the proprioceptive and forward motion of passive exercise increases CBF independent of the metabolic demands of active exercise.
Here, in procedural validation, participants (do not = 2) used a cycle ergometer to complete separate 20-min active and passive (via a mechanically controlled flywheel) exercise conditions and a non-exercise control condition. Electromyography showed that passive exercise did not increase agonist muscle activation or ventilation or gas exchange variables (ie, V̇O).two and V̇COtwo).
In the main experiment, participants (do not = 28) completed the same exercise and control conditions and transcranial Doppler ultrasound showed an increase in CBF through the middle cerebral artery during active and passive exercise (but not the control condition) (Ps < .001); although the magnitude is smaller during passive exercise.
It should be noted that before and immediately after each condition antisaccade responses are active (P < .001) and passive (P = .034) exercise improved oculomotor performance of executive function, while no benefit was observed in the control condition (P= .85).
Therefore, the results support converging evidence that passive exercise “increases” the oculomotor performance of executive function and that increased CBF mediates this benefit.