Keeping fit

Improving the body by care and training. Physical fitness means being able to carry out daily activities comfortably and face occasional physical challenges with a minimum of fatigue and discomfort. Signs of unfitness are a sedentary occupation, frequent tiredness, not able to keep up with others of the same age, avoidance of physical activity because it is too tiring, shortness of breath or fatigued when walking a short distance.

Until the time of the Industrial Revolution, strenuous physical activity was an integral part of daily life-in work as well as in religious, social, and cultural expression. When the Agricultural Revolution diminished work-related physical activity, the healers, and philosophers of the time questioned whether long life and health could be maintained with a decreased level of exercise.

Lack of physical inactivity is the second most serious threat to health in developed countries, and a sedentary lifestyle is one of the 10 leading causes of death and disability. The World Health Organization (WHO) estimates that the percentage of adults living in developed countries who are sedentary "or nearly so" has reached an astonishing 60-85%. A report published by the Centers for Disease Control and Prevention (CDC) in March 2001 revealed that just 25% of adults met government recommendations for physical activity in 1998. The current lack of enthusiasm for exercise is also a problem in the younger generation, as research suggests that less than one-third of young people are active enough to benefit their present and future health and wellbeing.

Regular exercise can produce more energy, a better quality of life, a healthier body composition, better balance and coordination, improved sleep and longer life expectancy. Exercising regularly and staying physically active can prevent or delay serious problems like high blood pressure and coronary artery disease, stroke, type 2 diabetes, cancer, bone loss and osteoporosis and colon cancer, but only vigorous physical activity is associated with greater longevity. These demanding exercise regimens, that increase the resting metabolic rate sixfold or more, include fast walking, jogging, tennis singles, lap swimming and fast cycling.

A total of 30 minutes' brisk walking or cycling on most days of the week, even if carried out in 10-15 minute episodes, is effective in providing health benefits. The average trip by walking in Europe is about 1.5 km and the average cycling trip is about 3.5 km, each taking about 15 minutes to make: two such trips each day would be enough to provide the recommended "daily dose" of physical activity.