Technology is rapidly reducing the necessity for physical activity as part of everyday life. Many modern conveniences (e.g., moving sidewalks, escalators) contribute to sedentary lifestyles and the overall health issues that accompany them. Only 21% of Americans are meeting the recommended guidelines for aerobic and muscle-strengthening activity, and half (50%) of adults participate in 30 minutes of moderate physical activity five or more times per week, which is the minimum recommendation.
The Physical Activity Guidelines for Americans are as follows:
- Children and adolescents: Children and adolescents should engage in 60 minutes or more of physical activity each day.
- Aerobic: Most of the 60 or more minutes per day should be either moderate- or vigorous-intensity aerobic physical activity and should include vigorous-intensity physical activity at least 3 days a week.
- Muscle-strengthening: As part of their 60 or more minutes of daily physical activity, children and adolescents should include muscle-strengthening physical activity on at least 3 days of the week.
- Bone strengthening: As part of their 60 or more minutes of daily physical activity, children and adolescents should include bone-strengthening physical activity on at least 3 days of the week.
- Adults: Adults should avoid inactivity on all days of the week. Some physical activity is better than none, and adults who participate in any amount of physical activity gain some health benefits.
Physically active lifestyles are especially beneficial for individuals with type 2 diabetes to improve overall health and to reduce the risk of the chronic complications associated with diabetes. Exercise improves the action of a person’s naturally produced insulin by increasing the sensitivity of insulin receptor sites. Exercise also enhances glucose uptake without requiring insulin by skeletal muscle cells clearing glucose from the blood. When managing type 1 diabetes mellitus, the type of exercise and timing must be balanced with food and insulin injections to prevent reactions caused by drops in blood glucose levels.
Exercise is extremely beneficial for weight management in the following ways: (1) it helps to regulate appetite; (2) it increases the basal metabolic rate; (3) it reduces the genetic fat deposit set point level; and (4) it is critical for weight-loss maintenance. Together with a well-planned diet, physical exercise improves the energy balance in favor of increased energy output. Fat is used efficiently as the primary fuel source during lower-intensity aerobic exercises such as walking, jogging, swimming, and light cycling, though moderate to higher intensity excise will result in higher caloric expenditure within the same time frame.
Weight-bearing exercises (e.g., walking, running) help to strengthen bones by increasing osteoblast activity.
The weight-bearing load increases calcium deposits in bone, thereby increasing bone density and reducing the risk for osteoporosis. While the benefits of exercise on bone density are most notable during the peak bone growth periods of adolescents and young adults, older adults are encouraged to engage in weightbearing exercise regularly to prevent further decreases in bone mineral density. However, excessive forms of training can have a destructive effect in which bone density is lost as a result of overtraining or undernutrition, or both.
Exercise stimulates the production of endorphins. These natural chemicals decrease pain and improve mood, which may include an exhilarating type of “high.” Mental health benefits from physical activity are persistent throughout life. Recent studies have shown not only that exercise can lower one’s risk for depression and anxiety disorders but also, as individuals age, that physical activity is associated with a lower risk of Alzheimer’s disease, dementia, and Parkinson’s disease, and can increase one’s overall quality of life.