Physical activity

Regular physical activity is a vital part of a healthy lifestyle, ideally consisting of a total of at least 30 minutes (and preferably 60, especially if weight loss/weight control is an issue) of aerobic activity on most (or all) days. 

To help yourself stay with an exercise program, experts recommend the following:
• start slowly.
• vary your activities; make it fun.
• include friends and others.
• set specific attainable goals and monitor progress.
• set aside a specific time each day for exercise; build it into your routine, but make it convenient.
• reward yourself for being successful in keeping up with your goals.
Consider applying the dietary principles of variety, balance, and moderation to your exercise plan:
• variety: enjoy many different activities to exercise different muscles.
• balance: different activities have different benefits, so balance your exercise pattern. For overall fitness, you need exercises that build cardiovascular endurance, muscular strength, and flexibility.
• moderation: exercise to keep fit without overdoing it. You don’t need a heavy workout every day to achieve fitness.

Health problems that require medical evaluation before beginning an exercise program are obesity, cardiovascular disease, hypertension, diabetes, shortness of breath after mild exertion, and arthritis.

During the first phase of a fitness program to promote health, you should begin to incorporate short periods of physical activity into the daily routine. This includes walking, taking the stairs instead of the elevator, house cleaning, gardening, and other activities. 

Once you can perform physical activity for 30 minutes per day, turn your attention to more specific goals, such as increasing muscle mass and strength, to reap even more benefits. Aerobic, strength, and stretching activities are included, as well as considerations for duration, frequency, intensity, and progression.

Begin by warming up with 5 to 10 more minutes of low-intensity exercises, such as walking, slow jogging, or any slow version of the anticipated activity. This warms up your muscles so that muscle fi laments more easily slide over one another to increase range of motion and decrease the risk of injury.

As people start exercising regularly four or five times per week, they experience a “training effect.”
Initially, these individuals might be able to exercise for 20 minutes before tiring. Months later, exercise can be extended to an hour before they feel tired. During the months of training, muscle cells have produced more mitochondria and thus can burn more fat. Training also increases the number of capillaries in muscles, which increases oxygen supply to the muscles.
As a result, lactic acid production from anaerobic glucose metabolism decreases. Lactic acid contributes to short-term muscle fatigue, so the less lactic acid produced, the longer the exercise can be sustained. Other contributors to the training effect include increased aerobic efficiency of the heart and muscles and elevations in muscle triglyceride content, with an enhanced ability of muscles to use triglycerides for energy needs.