Summary: Passive exercise increases cerebral blood flow and improves executive function, providing the same cognitive benefits as more active exercise.
Source: University of Western Ontario
A new study by Western kinesiology graduate students found that passive exercise leads to increased cerebral blood flow and improved executive function, providing the same cognitive benefits as active exercise.
Posted in Psychophysiologythe study is the first to examine whether there would be brain health benefits during passive exercise where a person’s limbs are moved via an external force – in this case, bicycle pedals pushed by a mechanically driven flywheel.
In a 20-minute session with healthy young adults, the team assessed executive function at baseline, before participants exercised, and compared data after exercise. They found an improvement in executive function of the same magnitude for both passive and active exercise conditions, with no increase in heart rate or diastolic blood pressure.
Executive function is a higher-order cognitive ability that enables people to make plans and support the activities of daily living. People with mild cognitive impairment, such as people with early-stage symptoms of Alzheimer’s disease, may have their executive function negatively affected.
Previous research has shown that active exercise, where a person activates their muscles of their own volition, can increase blood flow to the brain and improve executive function. Passive exercise also increases blood flow to the brain, but this is much less documented.
“In terms of passive exercise, we could only speculate on the outcome because this type of research had never been done before,” said Matthew Heath, professor of kinesiology and supervisor of the study.
During passive exercise, a person’s limbs move and their muscle receptors are stretched. This information is sent to the brain, indicating that more blood is needed in moving areas of the body and in connected regions of the brain. This increase in cerebral blood flow, although significantly less than that achieved with active exercise, produced improvements in executive function of a similar magnitude, an exciting result for the researchers.
“The potential impact for those with or without mobility could be profound. If done consistently, the increased blood flow to the brain and the resulting improvement in executive function will hopefully become a cumulative effect that has a significant impact on cognitive health and executive function,” explained Heath.
Further study could be improved by examining whether the benefit for executive function persists at longer time intervals after exercise, as well as by including more diverse participants (those who are older or whose health is compromised , for example).
Heath and his team see great potential in the use of passive exercise in long-term care homes or in rehabilitation programs for people recovering from musculoskeletal injuries, who cannot perform weight-bearing exercise.
The study was led by master’s student Mustafa Shirzad and co-authored by graduate students Benjamin Tar, Connor Dalton, James Van Riesen and Michael Marsala. Heath was the corresponding author.
About these exercises and brain health research news
Author: Kim McCready
Source: University of Western Ontario
Contact: Kim McCready – University of Western Ontario
Image: Image is credited to University of Western Ontario
Original research: Access closed.
“Passive exercise increases cerebral blood flow velocity and supports a post-exercise executive function advantage” by Mustafa Shirzad et al. Psychophysiology
Passive exercise increases cerebral blood flow velocity and supports a post-exercise executive function benefit
Executive function involves high-level cognitive control supporting activities of daily living. The literature has shown that a single bout of exercise involving voluntary muscle activation (i.e. active exercise) improves executive function and that an increase in cerebral blood flow (CBF) may contribute to this benefit. .
However, it is unknown whether involuntary exercise (i.e., passive exercise) in which an individual’s limbs are moved via an external force causes a similar benefit in executive function. This is an important question given that proprioceptive and predictive training of passive exercise increases CBF independent of the metabolic demands of active exercise.
Here, in a participant validation procedure (not = 2) used a bicycle ergometer to perform active and passive exercise conditions separated by 20 minutes (via a mechanically driven flywheel) and a no-exercise control condition. Electromyography showed that passive exercise did not increase agonist muscle activation or increase ventilation or gas exchange variables (i.e., V̇O2 and V̇CO2).
In a main experiment, participants (not = 28) performed the same exercise and control conditions and transcranial Doppler ultrasound showed that both active and passive exercise (but not the control condition) increased CBF through the middle cerebral artery (ps<.001); although the magnitude was less during passive exercise.
Notably, the anti-saccade reaction times before and immediately after each condition showed that the active (p < .001) and passive (p = 0.034) exercise improved an oculomotor measure of executive function, whereas no benefit was seen in the control condition (p= 0.85).
Accordingly, the results show that passive exercise “boosts” an oculomotor measure of executive function and supports the converging evidence that increased CBF mediates this benefit.