Alzheimer’s disease (AD) is a progressive neurodegenerative disorder that affects millions of individuals worldwide. Currently, there is no cure for AD, and the available treatments only provide temporary relief of symptoms.

Therefore, preventing or delaying the onset of AD is crucial for reducing the global burden of this disease. One potential approach to achieving this goal is through lifestyle interventions, particularly exercise and physical activity. In this article, we will explore the scientific evidence on the relationship between fitness and Alzheimer’s disease.

What is Alzheimer’s disease?

Alzheimer’s disease is a neurological disorder that primarily affects the memory and cognitive function of individuals.

AD is characterized by the accumulation of abnormal protein deposits, such as amyloid-beta and tau, in the brain, leading to the destruction of brain cells and the loss of neuronal connections. As a result, individuals with AD experience progressive decline in thinking, memory, and reasoning abilities, as well as changes in mood and behavior.

What is fitness?

Fitness refers to the overall health and well-being of individuals, including their physical, mental, and social aspects.

In particular, physical fitness is the ability of an individual to perform physical activities and exercise without undue fatigue, indicating the strength, endurance, and flexibility of the body. Physical fitness can be improved through regular exercise and training, such as aerobic and resistance exercises, stretching, and balance training.

What is the relationship between fitness and Alzheimer’s disease?

The relationship between fitness and Alzheimer’s disease is complex and multifaceted, involving various biological, psychological, and behavioral factors.

However, several studies have suggested that physical fitness might play a protective role in reducing the risk of AD, delaying its onset, and improving the overall cognitive function of individuals with AD.

Exercise and brain health

Exercise has been shown to have beneficial effects on the brain’s structure, function, and plasticity, which could explain its effects on AD.

Exercise promotes the growth of new neurons and synapses, increases cerebral blood flow and oxygenation, reduces inflammation and oxidative stress, and enhances neurotrophic factors such as brain-derived neurotrophic factor (BDNF), which is essential for learning and memory. In addition, exercise can help to improve mood, reduce stress and anxiety, and boost self-esteem and social interaction, all of which are relevant to brain health.

Evidence-based recommendations for physical activity

The World Health Organization (WHO) recommends that adults aged 18-64 years should engage in at least 150 minutes of moderate-intensity aerobic physical activity, or 75 minutes of vigorous-intensity aerobic physical activity, per week, preferably spread throughout the week. In addition, adults should perform muscle-strengthening activities involving major muscle groups on two or more days per week, emphasizing moderate or high-intensity exercises.

The guidelines also encourage reducing sedentary behavior and increasing physical activity for older adults and people with disabilities.

Clinical trials on exercise and Alzheimer’s disease

Several clinical trials have investigated the effects of exercise interventions on cognitive function, brain structure, and biomarkers of AD in individuals at risk or with early stages of AD.

For example, a randomized controlled trial of 160 sedentary adults at risk of AD showed that a six-month aerobic exercise intervention improved executive function and cerebral blood flow in the brain compared to a stretching and toning control group. Similarly, a six-month resistance exercise intervention in 86 individuals with mild cognitive impairment (MCI) or early AD showed improved memory and hippocampal volume compared to a stretching and balancing control group.

Conclusion

The relationship between fitness and Alzheimer’s disease is an important area of research that has shown promising results in both animal and human studies.

Regular physical activity, particularly aerobic and resistance exercise, may help to maintain cognitive function, reduce the risk of AD, and delay its onset. However, more research is needed to establish the optimal type, intensity, and duration of exercise interventions for different populations, as well as to explore the underlying mechanisms of the effects of exercise on brain health and AD.