Even low levels of leisure-time physical activity can prevent stroke in the long term

By Dr. Priyom Bose, Ph.D.Mar 6 2024Reviewed by Danielle Ellis, B.Sc.

Recently, scientists conducted a systematic review and metaanalysis to understand better whether different levels of leisure-time physical activity (LTPA) prevent stroke. This review is available in the Journal of Neurology, Neurosurgery and Psychiatry study.

The review was conducted by obtaining all relevant articles available in PubMed and Scopus databases. It must be noted that only articles that were published in English were considered in this study. 

A total of 3,064 articles were obtained in the original search. After removing the duplicates and matching them with eligibility criteria, 15 articles comprising 16 cohorts were included in the study. For quantitative analysis, six additional articles were included. The quality of the cohort studies included in this systematic meta-analysis was evaluated using the ROBINS-I tool.

Physical activity and stroke

Stroke is a life-threatening condition that occurs when blood flow is cut off to a part of the brain. It is one of the leading causes of mortality and morbidity in the world. Therefore, it is important to control the factors that increase the risks of stroke.

Many studies have shown that physical activities (PA) reduce the risk of stroke. PA is performed in wide-ranging intensities, frequencies, and duration. Both moderate and high levels of LTPA prevent stroke incidence and decrease mortality rates. In comparison to low-active individuals, the highly active population is at a lesser risk of ischaemic and hemorrhagic stroke.

Mechanistically, PA is associated with elevated levels of neurotrophins, which have anti-inflammatory and anti-thrombotic functions. Brain-derived neurotrophic factor and insulin-like growth factor 1 have been linked with neuroprotection and promotion of synaptic plasticity, neoangiogenesis, and neurogenesis. PA also alleviates common cardiovascular risk factors, such as dyslipidemia, obesity, hypertension, and diabetes.

As per international recommendations, individuals must perform ≥150 minutes of moderate exercise or ≥75 minutes of vigorous activity every week to prevent cardiovascular diseases, including stroke. Since too much LTPA might enhance the risk of cardiovascular events, it is important to understand the precise amount or a dose–response effect of LTPA to prevent stroke effectively.

It has been observed that only one out of four adults meet the minimum LTPA levels as per the international guidelines. Therefore, it is important to understand the benefits of smaller than recommended PA in preventing stroke.

The effect of different levels of physical activity in preventing stroke

In comparison to no activity, LTPA reduces the risk of stroke by 18% to 29%, depending on the intensity. Furthermore, the effect of LTPA with regard to the reduction in the risk of stroke was found to be independent of sex and age. Therefore, a very low level of LTPA is better than no activity in preventing the risk of stroke.

Inactivity contributes to around 8% of global mortality. To promote a better quality and healthy life, many campaigns, such as Life’s Essential, have been designed to promote the importance of physical activities. Since previously there was no consensus about the effect of a minimum level of LTPA, the current observation about the usefulness of even low PA in decreasing the risk of stroke could be extremely helpful. Furthermore, this information would be positively beneficial for individuals with restricted physical capacities and those with psychological and socioeconomic limitations.

The findings of this review are in line with 2020 WHO evidence-based recommendations that highlight some PA is better than none. Notably, this systematic review quantified how low LTPA decreases the risk of stroke. Although no dose-response curve of LTPA associated with risks of stroke was available, the authors retrieved a dose-response curve with approximated data linked to occupational and recreational activity. This data was obtained from the meta-analysis of the Global Burden of Disease on the risk of ischaemic stroke and other diseases.

The majority of previously published meta-analyses concluded that an increase in the levels of daily PA resulted in a reduction in the risk of ischaemic stroke. Although many studies debated and discussed the best pattern of PA for preventing stroke and decreasing mortality rates, this study highlighted that any pattern and frequency would provide beneficial effects. For instance, the 'weekend warrior’ pattern of PA that is associated with infrequent and intense PA resulted in the prevention of many disease incidences.

Several studies revealed that women are usually less active than men. Therefore, information about the beneficial effects of any level of PA, irrespective of age and sex, would encourage individuals to incorporate some form of PA in their lifestyle. 

Conclusions

The current systematic review has some limitations, including consideration of studies irrespective of their heterogeneity in the LTPA definition. Furthermore, these studies exhibited different methods for recording LTPA levels.

Despite the limitations, this study highlighted that in comparison to non-activity, any level of recreational PA has a beneficial effect on reducing the risks of stroke. It recommends campaigns to promote any level of PA that would reduce the risk of stroke in the general population.