Physical Activity and Brain Health: Integrating the Evidence Base into Workplace Health Promotion

Introduction

Being physically active is one of the most important lifestyle behaviors people can engage in to maintain their physical and mental health and well-being. Nearly all individuals can benefit from regular aerobic and muscle-strengthening physical activity. ¹ Regular physical activity helps prevent and manage chronic disease and associated risk factors, has positive effects on mental health and cognitive function across the lifespan,^1,2 and can reduce the risk of cognitive decline. ³ The purpose of this paper is to examine the benefits of physical activity on brain health and highlight the importance of integrating physical activity promotion, policy, and environmental supports into worksite health promotion efforts to help employees and their families on their journey toward active living.

The Relationship Between Physical Activity and Brain Health

The brain and body are intimately intertwined. ⁴ Movement of the body through physical activity behavior plays an integral role in childhood brain development ⁵ and bolsters cognitive performance for adults thereby positively impacting workplace productivity. ⁶ The social benefits of physical activity and its related positive impact on cognitive performance are also well established.^7,8

There is accumulating evidence demonstrating the importance of physical activity in the prevention and treatment of several psychological and neurological conditions.^9-11 The Physical Activity Guidelines for Americans ¹ provides general guidance regarding how to be physically active to improve cognition. The guidelines recommend acute bouts of moderate-to-vigorous intensity physical activity, which benefit cognition transiently during the post-exercise recovery period. The acute effects of physical activity can affect mood states, self-rated memory, and processing speed.^12,13

Long-term effects of physical activity include reducing the risk of cognitive impairments, delaying degenerative diseases of the brain (e.g., dementia), exerting anti-depressive effects, improved cognitive processes and memory, and being a generative force in inducing a sense of well-being. ¹³ Accumulating evidence demonstrates that physical activity is an important non-pharmacological treatment for a host of psychological and neurological conditions.^10,11 In fact, the John W. Brick Foundation produced a 2022 report ⁹ summarizing the results of 30 years of published scientific research examining the relationship between exercise and brain health. Of the 720 randomized controlled trials included in the analysis, 89% reported a statistically significant positive relationship between exercise and mental health.

Anxiety/Depression

Depression and anxiety are the 2 most studied mental illnesses, and both respond to exercise treatment. Depression generally responds well to moderate-to high-intensity aerobic exercise. ⁹ Anxiety disorders respond to mind-body practices--like Tai Chi or yoga--although there is evidence that they respond positively to aerobic exercise as well. ⁹

Laboratory research is being conducted to determine the exact mechanisms by which various types of exercise benefit brain health and function, reducing mental illness symptoms such as anxiety and depression. This research is making it increasingly clear that there are very complex and integrated systems of communication between the body and mind. With respect to anxiety and the mind-body exercise modalities, the mindfulness and breath work that are typically part of these practices appear to reduce the stressful background thoughts characteristic of these disorders. ⁹ This reduces stress hormones released into the body and the accompanying sensations and reactions. ⁹

There is emerging research suggesting the connection between the working muscles and the brain, mediated by what are called exercise myokines. ⁹ Myokines are small signaling peptides released from working muscles that can have effects on the other major systems of the body. Myokines act as hormones do. They are released from one location in the body and move to another location, where they have an effect. Aerobic exercise appears to produce myokines that, in a chain of molecular signaling events, positively influence the growth and health of neurons in the brain, especially those parts that contribute to depression.

The John W. Brick Foundation ⁹ recommends 30 to 45 minutes of moderate to vigorous aerobic exercise, 3 to 5 times per week for all adults diagnosed with depression. For anxiety, the Foundation recommends Tai-Chi, yoga, or other mind-body exercises, with additional aerobic or strength training. These findings apply to children as well, for the same biological reasons. ¹⁴ Children who participate in 3 to 5 sessions of vigorous activity of 30 to 45 minutes each week experience the same improvement in mood as adults and also experience better concentration. ¹⁴ Researchers have consistently reported that school-age children who get consistent aerobic exercise most days of the week in school perform better on standardized tests and show fewer behavioral problems than their physically inactive counterparts. ¹⁴

Cognition, Dementia, and Other Neurologic Conditions

Adults 60 years or older who regularly engage in physical activity experience a reduced risk of cognitive decline and functional limitation. Similarly, they experience an increased likelihood of improved cognitive functioning and quality of life, as well as healthy aging. ¹⁵ The prevalence of all-cause dementia, Alzheimer’s dementia, and vascular dementia are projected to multiply over the next couple decades. Lifestyle behaviors play a large role in the prevention of dementia, with physical inactivity being one of the 12 modifiable risk factors for dementia identified by the 2020 Lancet Commission on dementia prevention, intervention, and care that account for 40% of worldwide dementia. ¹⁶ A 2021 National Plan to Address Alzheimer’s Disease from the U.S. Department of Health and Human Services recommends reducing sedentary behavior and increasing physical activity to prevent Alzheimer’s disease. ¹⁷

A physically active lifestyle has been proposed to reduce the risk of dementia through several pathways, including decreasing the production of β-amyloid and/or increasing removal of β-amyloid, improving brain blood flow and vasculature, increasing glucose metabolism in the brain, and improving antioxidative processes and inflammation in the brain. Further, physical activity benefits one’s health by improving sleep, stress levels, mood and cardiovascular risk, all of which promote a healthier brain. ¹⁸

Further, research has pointed to an inverse dose-response relationship between physical activity and dementia when assessing both mid-life physical activity levels ¹⁹ and physical activity levels in older age. ²⁰ Iso-Markku and colleagues demonstrated a 20% reduction in dementia risk among middle-aged individuals for those who engaged in “high” physical activity levels compared to those who engaged in “low” levels of activity. ¹⁹ In fact, one population-based study identified that an optimal amount of vigorous physical activity (140 minutes per week) can significantly reduce mortality due to Alzheimer’s disease, potentially preventing 12 238 Alzheimer’s related deaths each year in the US. ²¹

As physical activity can benefit one’s muscular strength, motor function, emotional health, and quality of life, there are significant advantages of physical activity to individuals with neurological impairment such as stroke, ²² Huntington’s disease, ²³ Parkinson’s disease, ²⁴ and multiple sclerosis. ²⁵ Accordingly, physical activity often serves as a mechanism to prevent, delay, and manage neurologic disease and promote brain health.

Integration of Physical Activity into Worksite Health Promotion

Given the importance of physical activity on brain health, employers should integrate physical activity promotion and tailored physical activity prescriptions for employees into benefit design and programmatic offerings. However, the job-related levels of physical activity should be considered. ²⁶ In some cases, activity levels need to be complemented with periods of rest. In other cases, increased levels of movement need to be introduced to counter the impact of prolonged periods of sedentary behavior. Hence, assessment of context is necessary.

There is some evidence that high levels of occupational physical activity are associated with increased risk for cardiovascular disease and all-cause mortality, and this paradox with recommendations requires further research and understanding and may have serious equity implications. ²⁷ It is critical to supplement national physical activity surveillance systems data with data about employees’ physical activity levels. These data could be used by employers to guide policy and systems changes, monitor health improvement, develop benchmarks, assess productivity and work performance, and demonstrate employer commitment to health promotion.

Policy/Systems Changes

In the United States, many industry, government, and non-profit sectors have prompted new working arrangements and environments since the COVID-19 pandemic. ²⁸ Employers and employees are responding to changing work environments, creating solutions for health and well-being, with particular focus on vulnerable employee populations and assessing the impact on health care costs and utilization. Addressing appropriate levels of physical activity and fitness across work and in leisure time can sustain workforce health and well-being.

Employers can lead the way in supporting healthy living with appropriate policy and systems changes. Strategies include tax incentives/subsidies for active transportation, fitness facility memberships or supervised exercise therapy, use of health savings accounts or flexible spending accounts for fitness memberships or exercise prescription based on medical necessity, ²⁹ and organizational level policies like flex-time, active meetings, workplace design to reduce sedentary time, and incentivizing and subsidizing active transportation to and from work.^28,30 The Physical Activity Alliance has a CEO Pledge prompting executives and directors to serve as role models, making physical activity and healthy movement a cultural norm in the workplace. Employers with employer-sponsored health insurance can support physical activity assessment, prescription, and referral to community resources for active living, increase access to preventive care and chronic disease management, integrate device-based measurement and remote-patient monitoring for physical activity and other measures of health, and support employees and their families with educational and financial resources for healthy living.

Benchmarking/Scorecards

Organizational health and well-being assessments, including scorecards, can be used to assess the effectiveness and comprehensiveness of worksite health and well-being initiatives. These assessments can help employers identify and assess their use of practices that support more effective health and well-being initiatives. Although many of these health and well-being practices are linked to the promotion of brain health, future research needs to identify how best and promising practices in worksite brain health promotion influence specific health, well-being, and business outcomes (e.g., productivity).

The HERO Health and Well-Being Best Practices Scorecard in Collaboration with Mercer© (HERO Scorecard) is developing a Brain Health best practice score from existing practices listed throughout the HERO Scorecard. This score is being designed to help organizations assess how they are doing in their promotion of brain health. Practices that are a part of this score will include workplace policies supporting physical activity, as well as a built work environment supporting physical activity options. Benchmarking data will be made available to allow organizations to compare their initiatives to similar organizations to help support their program development and strategic planning.

Conclusion

Increasing evidence demonstrates the acute and long-term benefits of physical activity on brain health, including reducing cognitive decline and dementia, increasing productivity, focus, and concentration, improved mood, and a reduction in symptoms associated with depression and anxiety. Employers would benefit from acting on this evidence to develop the appropriate programming, benefit design, and organizational policy and systems changes to support employees engaging in active living practices. More research is needed to provide specificity for physical activity prescriptions (frequency, intensity, type, and duration) to improve cognition and reduce risk for neurologic conditions. ² Future research should consider physical activity requirements for specific job-roles and elucidate specific exercise prescriptions that address the different aspects of brain health and cognition, supported by more comprehensive benchmarking and population-level data monitoring. Such research will inform even more effective programming, policy, environment, and systems support for employers, employees, and their families on their journey toward active living and brain health.