A new study finds that doing half-squats for one minute every 20 minutes to break up long periods of sitting can improve blood flow to the brain, thereby improving cognitive function and concentration. This simple exercise can be done at work or at home to promote brain development.

We all know that sedentary behavior - such as sitting at a desk all day or sitting on the couch watching TV for long periods of time - can have a negative impact on our health. Previous research has shown that prolonged sitting can even reduce blood flow to the brain, impairing executive function, a set of skills critical for planning, concentration, memory and multitasking. And studies have found that increasing blood flow to the brain can reduce the risk of dementia.

A new study examines the effects of prolonged sitting and non-sitting on cerebral blood flow and executive function.

The researchers recruited 20 healthy young adults (45% female) with an average age of 21 years. They excluded people who regularly engage in moderate or strenuous exercise, smokers, people with a history of cardiovascular and cerebrovascular diseases, and people who are taking drugs that affect cardiovascular and cerebrovascular health.

The participants were divided into a control group, which sat for three hours without interruption, and an intervention group, which sat for the same amount of time but did half-squats for one minute every 20 minutes. When doing a half-squat, participants cross their arms in front of their chest and bend their knees to 90 degrees, repeating every 4 seconds. As a crossover study, participants trained in both groups for a period of time.

Blood pressure (BP), heart rate, and blood flow through the internal carotid artery (ICA) (which accounts for 75% of total blood flow to the brain) were measured at intervals during sitting. Before and after sitting, participants completed the Visual Analogue Scale (VAS) (which measures mental fatigue, attention, and motivation), the Color-Word-Strope Test (CWST) (which measures executive processing), and the Path Making Test Part B (TMT-B) (which measures cognitive and executive functions).

In the CWST test, subjects need to quickly identify whether "red", "blue", "yellow", "green" and "black" are printed with colored ink and correspond to written text. TMT-B requires students to trace lines corresponding to the correct combination of letters and numbers: A-1, B-2, C-3, etc.

The researchers found that people who performed intermittent squats responded faster to the incongruent (words were inconsistent with the printed colored ink) and congruent (colors were consistent with the words) conditions of the CWST and completed the TMT-B faster than controls. However, there was no change in the accuracy with which the two groups completed each task.

The control group showed a more pronounced decrease in concentration and a greater increase in mental fatigue than during exercise. When participants sat still for 10 to 180 minutes, ICA blood flow decreased by 3.7%, while it increased slightly (0.3%) when exercising.

The researchers said: "The main finding of this study is that for 3 hours of prolonged sitting, half-squat interruption can improve some aspects of executive function. This effect may be due to the preservation of ICA blood flow during half-squatting, which may also be responsible for maintaining arousal, concentration, and fatigue. These data provide potential mechanistic implications for understanding how cognitive performance is maintained during prolonged sitting."

The researchers noted some limitations of their study. Participants in the control group were asked to "not move their legs or fidget," which does not represent real-world conditions. While this more effectively isolates the effects of the control and intervention groups on participants, it may limit the validity of the study. Additionally, they only tested one area of ​​cognitive function using both testing methods; other areas, such as attention, memory and decision-making, may be affected by prolonged sitting. Future research needs to evaluate these factors.

However, researchers say this simple and easy exercise may have some benefits. "The current findings suggest that, compared with uninterrupted sitting, half-squatting, a simple and feasible exercise strategy, can improve certain aspects of executive function and inhibit the increase in fatigue, thus maintaining ICA flow during acute prolonged sitting," the researchers said.

The research was published in the journal Applied Physiology.