By jumping straight into a workout, you run the risk of injury. Always begin your aerobic workout with slow steady movements to warm up your muscles and ease your body into the main exercise. The warm-up phase of your workout should last about five to ten minutes and should be a slower, more gentle version of the full exercise you will perform. An easy warm-up if you are running is to simply walk or jog slowly.
How often you exercise matters. Most experts agree that as little as three days of aerobic exercise each week benefits your health, but you may need to exercise more, depending on your specific goals. To lower cholesterol rates, the Mayo Clinic recommends 30 minutes of aerobic activity on five days a week. On the other hand, overtraining can be harmful. Take at least one day off per week for rest and recovery. If you're not sure, talk with your doctor or trainer to determine what your specific needs are.
Intensity measures how hard you are working out. Intensity ranges from a restful state to working at your maximum capacity -- when it is impossible for you to work any harder. Work out at a moderate intensity, which is in the middle of the scale to minimize the risk of injury and keep you motivated. Your aerobic workout can be at a single intensity for the entire duration, or you can alternate lower to moderate intensity exercise with bursts of maximum intensity, which is known as interval training.
Endurance is the ability to work out at a moderate to high intensity for an extended length of time. Aerobic endurance builds up over time. If you have been working out for years, you will be able to exercise at a higher intensity and for a longer amount of time than someone who is new to exercise. Aerobic endurance is beneficial to the strength of your heart and lungs as they take in more oxygen to support your activity level, making your every day tasks, like climbing stairs, easier.
Opposite of the warm-up, the cool-down is after your main exercise. You must give your body a chance to literally cool down your muscles from the heat you generated during your workout to avoid risk of injury. Like the warm-up, you will perform the same exercise but at a slower pace or intensity for five to 10 minutes before stretching the muscles you used during the exercise.