Exercise is defined as physical activity that is performed to develop or maintain fitness. Regular exercise along with proper nutrition are essential aspects of maintaining good health in people of all ages, including children. When children embrace fitness at an early age, they are more likely to remain active into adulthood and throughout their lives. Exercise increases body metabolism, helps oxygen to circulate and the intestines to function, and increases the ratio of muscle to fat. Regular exercise helps to maintain a healthy weight and increases strength, endurance and flexibility. It also increases energy, coordination and bone mass, and improves sleep. Remaining fit decreases the risk of numerous medical conditions and illnesses, including high blood pressure and cholesterol, type 2 diabetes, heart disease and osteoporosis (loss of bone mass).

Regular physical activity also appears to benefit children with chronic health issues. For instance, new research findings indicate that children with type 1 diabetes may improve their glucose (blood sugar) levels by engaging in regular exercise. Also, overweight teenagers – who are at risk of becoming obese and developing diabetes – can help prevent or delay onset of both conditions through regular strength training exercise, according to a new study.

The benefits of proper fitness are not just physical. Regular exercise also improves self-esteem, reduces stress and increases alertness. It provides opportunities for social interaction and teaches children numerous life lessons, such as perseverance, and setting and achieving goals.

There are three important aspects to fitness, regardless of age:

• Endurance. Any sustained aerobic (exercise that improves oxygen circulation) activity increases endurance. These are activities that cause faster heartbeats and heavier breathing. However, if these exercises cause breathing so heavy that it makes it difficult to talk, it is best to cut back. When done properly, these exercises increase the strength of the heart and improve the delivery of oxygen throughout the body. Many sports (e.g., soccer, swimming, running) and other activities involve aerobic activity. However, sports that involve very short bursts of activity may not provide long enough periods of sustained activity to be beneficial in increasing endurance.
  
  
• Strength. This involves exercises that increase muscle tone and strength. For adults, this often means lifting weights. However, for children, it tends to include exercises and activities such as push-ups, sit-ups, pull-ups, stomach crunches and climbing.
  
  
• Flexibility. Stretching exercises increase flexibility (the ability of muscles and joints to bend and move). Stretching is important both before and after endurance and strength exercises.

It is important for parents and/or children to speak with a pediatrician before a child begins any new fitness regimen, including athletic activities. A pediatrician can evaluate the child and help decide which activities are safe for the child’s stage of development. A pediatrician should also be consulted if the child complains of pain or appears overly fatigued for the amount of effort an activity requires.

Children need to drink plenty of fluids (e.g., water) before, during and after exercising. Different forms of exercise also require various different types of preparation. For example, any equipment (including play equipment such as swings and climbing bars) must be secure and safe. Safety equipment (e.g., helmets, pads) are necessary for many sports and activities, including bicycle riding. Many activities (e.g., sports, strength training) require close supervision by a qualified adult.

Exercise does not have to be strenuous to be beneficial. When exercise is fun, children will be motivated to continue the activity. Daily exercise can also be broken up into several sessions throughout the day.

Children are naturally active and often exercise even when performing everyday activities. For example, children exercise when they are playing tag and other physically active children’s games and during gym classes, sports and other activities (e.g., dancing, bicycling). They also exercise when performing many household chores, such as mowing the lawn, shoveling snow and cleaning the house.

However, many modern forms of entertainment (e.g., television, videos, computers, video games) encourage children to remain inactive and sedentary. It is best to limit sedentary time to provide more time for physical activity. Other methods of increasing a child’s amount of physical activity include having children take the stairs instead of the elevator and walk or ride their bicycle to school.

According to the Centers for Disease Control and Prevention (CDC), children tend to participate in less physical activity as they get older. The number of overweight or obese children is increasing, according to the CDC. In 2003, 17 percent of American children were overweight, up from 11 percent in 1994. Daily enrollment in high school physical education classes has decreased over time, from 42 percent in 1991 to 28 percent in 2003, the CDC reports. In addition, almost half of American children and adolescents do not participate in regular vigorous physical activity, according to the CDC. This is leading to an overall trend of fewer fit children and adolescents and more children who are overweight or obese.