The Best Medicine?

In addition to enhancing cognitive abilities, simply walking briskly for 2.5 hours each week (or about 30 minutes on weekdays) can lead to better blood pressure and cholesterol levels, increased energy, improved mood, and enhanced sleep quality, according to the American Heart Association.

An increasing number of studies indicate a direct connection between exercise and happiness, suggesting that physical activity may be a contributing factor to emotional well-being. Conversely, exercise can also help alleviate depression; even a short 10-minute walk can mitigate stress and anxiety. The evidence clearly shows that regular physical activity benefits overall health and reduces the risk of various health issues.

The effort required to reap these physical and mental rewards is not overwhelming; it doesn’t necessitate special gear or hours in the gym. The term “exercise” may even deter some inactive individuals. Health professionals should consider recommending “activity” as a means to enhance both physical and mental health before resorting to medication.

How Does it Work?

The exact mechanisms by which physical activity benefits brain health are not completely understood, but researchers are making progress.

According to Harvard Medical School, a vigorous workout promotes the release of chemicals that support brain cell health and stimulate the formation of new blood vessels in the brain. Additionally, exercise indirectly boosts mood, lowers stress, and improves sleep, all of which contribute to enhanced cognitive function.

The benefits of exercise can be seen in brain structure as well. Scott McGinnis, a neurologist at Brigham and Women’s Hospital and a neurology instructor at Harvard, notes that engaging in a consistent moderate-intensity exercise program over six months to a year is linked to increased volume in specific brain regions.

A meta-analysis examining exercise's effects on the hippocampus—a region crucial for memory and learning—revealed significant positive impacts on the left hippocampal volume for those who engaged in aerobic exercise compared to non-exercisers. This exercise prevented the typical shrinkage of the hippocampus, as reported in 2017 in the journal Neuroimage.

Protective Effect

Physical activity appears to offer a protective effect on the brain overall. A compelling study tracked the activity levels of 454 older adults who consented to donate their brain tissue posthumously. The research revealed that those who were more active—engaging in routine activities like housework—demonstrated better memory and cognitive skills. Moreover, the brains of less active individuals exhibited a higher presence of lesions associated with Alzheimer’s disease.

“Exercise is a cost-effective method to improve health, and our study indicates it may provide a protective effect on the brain,” stated Aron Buchman from Rush University Medical Center, the lead author of the study published in January 2019 in the journal Neurology. He emphasized, however, that the study does not definitively establish cause and effect; it is possible that cognitive decline may lead to reduced physical activity. More research is required to confirm if increased movement genuinely benefits brain health.

While further investigation is necessary, it is clear that some level of activity is better than none, and more activity yields even greater benefits.

A 2017 study published in Translational Psychiatry involving brain scans of 60 individuals aged 65 to 85 found that those who exercised on bikes three times a week for 12 weeks experienced significant changes in brain metabolism, preventing the accumulation of choline, which is linked to brain cell loss in dementia patients. The control group, which did not exercise, showed increased choline levels.

“Elevated choline could indicate neurodegenerative processes,” noted Silke Matura, a study leader from Goethe University Frankfurt. “Our findings suggest that regular aerobic exercise may have a neuroprotective effect by potentially slowing down neurodegeneration.”

The capacity for adults to generate new brain cells has been a subject of debate for years, but recent research seems to be leaning toward a consensus affirming this ability.

Broad studies in 2018 and 2019 confirmed that older adults can indeed produce new brain cells. A notable headline from a 2019 study stated: “Adult hippocampal neurogenesis is abundant in neurologically healthy subjects and declines sharply in Alzheimer’s disease patients.” Recent research on both rats and humans indicates that physical activity aids in this neurogenesis.

Strong Body, Strong Mind

If aerobic exercise can foster new brain cell growth, enhance memory, and improve clarity of thought, what about other exercise forms? Weightlifting has also shown potential benefits for brain health, although fewer studies have been conducted, and intensity appears to play a vital role.

Research led by Teresa Liu-Ambrose at the University of British Columbia examined the effects of cardio versus weight training on women showing early signs of dementia. The results indicated that only those who participated in weight training experienced notable improvements in both memory and executive functions. This contrasts with earlier findings that highlighted the benefits of cardio exercises for healthy individuals. Neuroimaging also revealed increased neural activity in brain areas responsible for memory and executive functions following weight training.

In a more demanding study, 100 men and women aged 55 to 86 with mild cognitive impairment underwent a weightlifting regimen twice a week for six months. They worked with heavy weights—80 percent of their maximum strength—and as they progressed, the weights increased. Compared to control groups, these increasingly fit seniors exhibited cognitive improvements that persisted even a year after the program ended.

“The stronger individuals became, the greater the benefits for their brains,” stated Yorgi Mavros, a researcher from the University of Sydney and lead author of the study published in the Journal of American Geriatrics. He emphasized the importance of frequent, high-intensity workouts to maximize strength gains and brain benefits.

Just About Any Activity is Good

The takeaway? Many researchers in this field echo a similar sentiment:

“I believe the evidence overwhelmingly indicates that engaging in physical activity is one of the best choices you can make for both your physical and mental health,” asserted Stern from Columbia University.

When asked if this understanding has motivated him to increase his activity levels, he replied, “I’ve made an effort to boost my weekly exercise. However, changing habits is challenging. One effective strategy is to incorporate external motivation, such as friends or a trainer waiting for you. Another is to find ways to integrate exercise into your daily routine. For instance, I walk to my office after buying lunch in the hospital cafeteria.”

Opting for stairs instead of elevators and including walks in your daily schedule is excellent advice—not only for brain health but for overall well-being. Additional research indicates that you don’t need to spend hours in the gym to achieve significant health benefits:

• Walking just one hour a week may enhance longevity.
• Short bursts of intense exercise, like climbing three flights of stairs multiple times a day, can improve fitness and mood.
• Remarkably, firefighters capable of completing 40 push-ups in a row had a 96 percent lower risk of cardiovascular disease compared to those who could only do 10.
• A mere 13 minutes of weightlifting three times a week can yield the same strength benefits as longer sessions.

Other studies have identified a variety of activities as beneficial for physical health.

Dancing: Research has shown that dancing not only helps prevent dementia and increases hippocampal volume but also outperforms traditional endurance workouts in enhancing balance among older adults.

Gardening: A single 20-minute gardening session—comprising tasks like cleaning, digging, raking, planting, and watering—has been linked to increased levels of brain-healthy growth factors in elderly South Koreans.

Anything? A February 2019 study involving 800 Swedish women found that those who engaged in high levels of physical activity were 52 percent less likely to develop dementia compared to inactive individuals. This activity could include walking, gardening, or biking for a minimum of four hours weekly, alongside regular intense exercise like running or swimming.

While it’s essential not to dismiss vigorous exercise, another study involving 1,462 Swedish women over time revealed that those with high fitness levels delayed the onset of dementia by an average of 9.5 years compared to those with moderate fitness.

No single study offers definitive proof, but collectively, the findings are clear: leading a sedentary lifestyle is unwise.