Mental Health and Well-being
In addition to physical health, mental health and well-being is also a concern of major significance. Globally, an estimated 264 million people suffer from depression, one of the leading causes of disability, with many of these people also suffering from symptoms of anxiety. Depression and anxiety have a significant economic impact; the estimated cost to the global economy is US $1 trillion per year in lost productivity. In 2010, worldwide, an estimated US $2.5 – 8.5 trillion in lost output was attributed to mental disorders. This sum is expected to nearly double by 2030 if a concerted response is not mounted. In view of this concern, the promotion of mental health and well-being have been explicitly included in the United Nations’ 2015–30 Sustainable Development Goals.
Clinical literature has recognized for years that physical exercise affects overall health and brain function. Recent research has established how voluntary exercise can increase levels of brain-derived neurotrophic factor (BDNF) and other factors, improving learning, mental performance, and enhancing/promoting brain plasticity. Another 2019 study provided strong support for the idea that physical activity has an important and likely causal role in reducing risk for depression, showing a 26% decrease in odds for becoming depressed for each major increase in objectively measured physical activity. The ‘increase’ in physical activity was further described as what a person might experience by replacing 15 minutes of sitting with 15 minutes of running, or 1 hour of sitting with 1 hour of moderate activity, like brisk walking.
Regular physical exercise increases blood flow, improves cerebrovascular health, and determines benefits on glucose and lipid metabolism carrying “food” to the brain. It enhances cognitive function in both younger and older adults, improves memory, and improves academic achievement in comparison to sedentary individuals. In older adults, physical exercise prevents cognitive decline linked to aging, and may reduce the risk of developing dementia and deterioration of executive functions, thereby helping older people to maintain independence throughout life.
It is clear that an active lifestyle decreases the risk of several chronic diseases and certain physical and mental disabilities, contributes to more efficient functioning of many of our body’s systems, and improves our overall quality of life. The positive benefits of regular physical activity are present throughout life, during childhood, adolescence, and adulthood. None of these benefits is more important than the critical role physical activity plays in weight maintenance throughout the life span.
Improving Our Lives
Besides the health implications, sedentary behavior contributes to complications and limitations in performing daily tasks. Regular exercise and fitness make our day-to-day activities (activities of daily living, or ADL’s) easier and more enjoyable. To accomplish this, the different components of fitness need to be addressed in a comprehensive exercise plan (see table below). Although the components of fitness are grouped as either health-related or skill-related, there is considerable crossover in both training and application. Aerobic exercise helps build cardiorespiratory endurance, which not only makes daily tasks like shopping, walking through a grocery store, or running for a bus easier, it also helps to make improvements in speed and power more likely. Improving body composition can also improve speed, agility, balance, and overall sports performance. Increases in agility, coordination, balance, and power help athletes perform at their peak and older individuals avoid falls. Improved flexibility has similar dual benefits, as it makes reaching down to pick up a dropped item easier, but can also reduce sport injury. Often referred to today as “functional” fitness, training to prepare the body for real life movements and activities is important. Training your muscles to work together prepares them for daily tasks by simulating common movements you might do at home. By participating in exercise and improving fitness, we not only improve our health, we improve our ability to participate in life.
Physical activity has positive effects on brain health at all stages of the lifespan and a growing body of literature indicates that it may enhance cognition, offer protection against neurodegenerative disorders, and reduce incidence and severity of many psychological conditions including the common mood disorders anxiety and depression.
Psychologically, the endorphins that are released during exercise help to improve mood, and make people feel less fatigued, depressed, or stressed throughout the day, even if the exercise lasts for as little as 10 minutes.
Furthermore, the inputs from the visual system as well as cognitive input may be able to act as a distractive stimulus, reducing the perception of exertion. It is likely that promoting attention to an external pleasant and green environment reduces awareness of physiologic sensations and negative emotions, thus minimizing the perception of effort, and making exercise seem easier. Additionally, mood is enhanced and perception of effort appears to be reduced in natural environments.
Outdoor exercise also helps maintain or improve the elasticity of the blood-carrying arteries, which allows for greater overall blood flow throughout the body. This may result in lower blood pressure and less stress on the heart. Similar effects are noted in the lungs, which benefit from regular exercise by being able to move oxygen and carbon dioxide in and out of the body more efficiently.
Another well-known benefit of outdoor exercise is increased bone density, which can prevent or reverse the onset of osteoporosis. Since bone is a living tissue, it responds to weight bearing exercise by becoming stronger, which may allow us to have greater mobility later in life. Being outdoors also provides access to fresh air, and provides a natural way for the body to absorb vitamin D from sunlight. This is especially important for those who are overweight or obese, as research suggests people who are overweight are more likely to be deficient in vitamin D.