Physical activity

Physical activity is defined as any movement produced by skeletal muscles that requires energy expenditure.

This concept covers all movements performed at any time of day or night. It is a vital component of public health and disease prevention. While many people use the term interchangeably with "exercise," they are not the same. Physical activity is a broad category that includes all forms of movement. Exercise is a specific subcategory of physical activity. It is defined as being planned, structured, repetitive, and purposeful. The main objective of exercise is to improve or maintain physical fitness or performance. In contrast, physical activity can be unplanned, unstructured, or random. It includes incidental activities integrated into a daily routine, such as cleaning or walking to a shop.

Movement occurs along a continuum of different intensities.

Scientists categorize these intensities using a standard measure called metabolic equivalents, or METs. This scale allows researchers to group activities based on how much energy they use. The first category is sedentary behavior, which includes sitting or lying down. The next level is light physical activity, such as slow walking or shuffling around a house. Moderate physical activity involves more effort, like brisk walking, jogging, or climbing stairs. The highest level is vigorous physical activity, which includes fast running, fast cycling, or sprinting. Depending on the individual, an activity may overlap these categories or change intensity completely.

Maintaining regular physical activity is essential for regulating body weight. It also provides significant benefits for mental, cognitive, and cardiovascular health. Conversely, physical inactivity is linked to several non-communicable diseases. These are illnesses that are not caught from other people, such as coronary heart disease, stroke, and diabetes mellitus. Inactivity is also associated with depression. The global impact of inactivity is massive. An analysis predicts that 500 million new cases of disease will occur globally between 2020 and 2030 if activity levels remain at current levels. This trend could result in more than US$300 billion in treatment costs.

Research shows that physical activity can serve as both prevention and therapy. For example, it has been shown to reduce anxiety and improve symptoms of irritable bowel syndrome. Different types of movement may be more effective for specific mental health needs. For people experiencing severe depressive episodes or anxiety disorders, long and short walks have proven most effective. For those with substance abuse disorders, bipolar disorder, or frequent psychotic decompensation, strenuous gymnastics and riding were found to be most effective. Even home-based exercise can help. Exercising with family members is associated with family well-being and resilience.

There are many ways to increase physical activity at a population level. Experts suggest investments in whole-of-school programmes and active transport. Active urban design and public education are also important. Workplaces and community-wide programmes can help people move more during the day. Reducing sitting time in the workplace is one way to address sedentary behavior. In 2019, nature-based physical activity in England had a significant economic value. It was estimated to have avoided £108.7 million in healthcare and societal costs. These costs were related to diseases like type 2 diabetes, colon cancer, and major depressive disorder.

Different forms of physical activity can be grouped into clusters based on their meaning.

Researchers Lundvall and Schantz identified several clusters in their 2013 study. These include competition and championship, nature encounters, and aesthetic-expressive activities. Other clusters include fitness gymnastics and play, everyday exercise, and various forms of physical training. Physical training can be divided into aerobic, anaerobic, strength, flexibility, and coordination training. Understanding these different clusters helps explain how people engage with movement in their leisure time.

The World Health Organization provides specific recommendations for different age groups. For children and adolescents aged 5 to 17, the goal is at least 60 minutes of moderate- to vigorous-intensity activity daily. For adults aged 18 to 64, the recommendation is at least 150 minutes of moderate-intensity aerobic activity per week. Alternatively, they can perform 75 minutes of vigorous-intensity aerobic activity. These bouts of aerobic activity should last at least 10 minutes each. Adults should also perform muscle-strengthening activities involving major muscle groups on two or more days a week. For adults aged 65 and older, similar aerobic goals apply, but those with poor mobility should focus on balance to prevent falls.

As of 2024, 31% of adults and 80% of adolescents do not meet these recommended levels.