Staying fit is largely a matter of eating a healthy diet and getting enough exercise. According to the Centers for Disease Control, a healthy adult should engage in no less than two hours and thirty minutes of aerobic exercise weekly, ideally working hard enough to noticeably raise the heart rate. Muscle-strengthening exercises for the legs, arms and core should be performed at least twice weekly. Another essential part of staying fit is eating a healthy diet, usually based mostly on whole grains and other complex carbohydrates, and containing at least five daily servings of vegetables and fruit. Fish, lean meats, and low fat or fat-free dairy products can normally be included in a healthy diet, though sugars and fats usually aren't recommended.
Staying active may be one of the best ways to maintain physical fitness throughout life. The Centers for Disease Control believes that children should start exercising at the age of six, and that most children need at least one hour of aerobic activity each day. Children are usually advised to participate in calisthenics, which can strengthen muscles, at least three times a week, and to participate in aerobic exercises such as jumping rope at least three times a week.
Adults generally need about two and a half hours of moderately strenuous exercise per week. The more strenuous the exercise, the less exercise is generally needed. Adults performing very strenuous exercise, such as jogging, swimming or playing team sports, may need as little as 75 minutes of exercise per week. Adults are generally advised to perform muscle-strengthening exercises, such as calisthenics, yoga or weight-lifting, at least twice a week.
Staying fit usually also involves eating a healthy diet. Exercise alone often can't prevent the nutritional deficiencies that can occur if inappropriate foods are eaten, or if calorie intake is inadequate. Most adults need between 1,500 and 2,000 calories per day. Nutritional experts believe that most of these calories should come from whole grains, like rice, barley, and wheat. Beans and legumes can also form part of the basis of a healthy diet.
The consumption of vegetables and fruits can be key to staying fit, since vegetables and fruits contain many of the vitamins and minerals needed for good health. Most experts recommend the consumption of at least five servings of vegetables and fruits per day. Lean meats, fish and low-fat or fat-free dairy products can also be consumed as part of a healthy diet. Experts often advise minimizing the dietary intake of meats and dairy, due to their often high fat content, especially saturated fat. They may also advise eating fish sparingly, since it could contain mercury and other contaminants.