Exercise is physical activity done regularly to improve, maintain, or slow the loss of fitness. Physical fitness is the capacity to perform physical activity with vigor and alertness and without undue fatigue. Fit people have more energy to pursue leisure activities. Fitness is also the degree to which people can withstand stress and persevere under difficult or emergency circumstances.
Regular exercise is one of the things that people can do to help prevent illness, preserve health and longevity, and enhance quality of life. Exercise comes in many forms and can vary in intensity of effort. With so many ways to exercise, almost everyone can participate in some way.
Benefits of Exercise
Regular exercise makes the heart stronger and the lungs fitter, enabling the cardiovascular system to deliver more oxygen to the body with every heartbeat and the pulmonary system to increase the maximum amount of oxygen that the lungs can take in. Exercise lowers blood pressure, somewhat decreases the levels of total and low-density lipoprotein (LDL) cholesterol (the bad cholesterol) and increases the level of high-density lipoprotein (HDL) cholesterol (the good cholesterol). These beneficial effects in turn decrease the risk of heart attack, stroke, and coronary artery disease. In addition, colon cancer and some forms of diabetes are less likely to occur in people who exercise regularly.
Starting an Exercise Program
People should consult their doctor before beginning competitive sports or an exercise program. Doctors ask about known medical disorders in the person and family members and symptoms the person has. They do a Physical examination, including listening to the heart with a stethoscope. This evaluation identity some of the rare young people who could have a previously unsuspected heart disorder that can lead to serious heart rhythm abnormalities or sudden, unexpected death with strenuous exercise. It also detects conditions that could restrict activities. For example, overweight people are more likely to develop musculoskeletal injuries after activities involving sudden starts and stops (such as tennis and basketball) as well as those that involve impact (such as jogging).
People older than age 40 who are starting an exercise program should report any diagnosis of heart disorders or arthritis and describe any symptoms of chest pain, shortness of breath, leg pains with walking, palpitations (awareness of heartbeat or irregular heartbeats, joint pain or swelling, and inability to exercise for long period (for example, because of weakness, shortness of breath, sweating, or leg pains). Certain drugs may limit the ability to exercise, such as beta-blockers, which slow heart rate, and sedatives, which can cause drowsiness and increase the risk of falling.
Conditions that make exercise too risky to recommend in children include heart inflammation (myocarditis), Which is uncommon. It increases the risk of sudden death due to heart dysfunction. Fever is another, because it impairs ability to exercise, may be a sign of serious illness, and may lead to heat-related illness such as heatstroke. Conditions that lead to dehydration (for example, vomiting and diarrhea) are also risky, because sweating during exercise can worsen dehydration.
Conditions that make exercise too risky to recommend and that occur mainly in adults include angina pectoris and a heart attack in the previous 6 weeks. People should take precautions when they have certain other conditions.