What Is Long-duration Aerobic Exercise?

Aerobic exercise is a necessary component in a fitness program because of its long-term health benefits such as strengthening the heart and lungs, and helping to reduce and maintain a healthy body weight. There are two types of aerobic exercise -- short duration and long duration. Both offer health benefits, but in slightly different ways.

Long Duration

Long-duration aerobic exercise, also called steady-state exercise, is performed at a low- or moderate-intensity level for an extended period of time, typically 20 minutes or more. This form is beneficial for individuals at any level of fitness because it raises and then maintains a slightly elevated heart rate. Long-duration aerobic exercise can be performed using any exercise that maintains a steady level of intensity such as walking, jogging, elliptical training, cycling and swimming.

Short Duration

Short-duration aerobic exercise, also called interval training, is vigorous or high-intensity exercise performed in short bursts. These high-intensity intervals can last anywhere from 20 seconds to three minutes, followed by lower-intensity recovery intervals that are equal to or double the length of the high-intensity interval. The intervals are typically repeated five to 12 times, for a total exercise time of less than 20 minutes, not including warm-up and cool-down.

Most Effective at Burning Fat

Determining the most effective form of aerobic exercise to burn fat and calories can be difficult. The optimal fat-burning zone is between 55 and 72 percent of your maximum aerobic power, according to Jack H. Wilmore and David L. Costill, authors of "Physiology of Sport and Exercise." At this intensity level, a large percentage of calories burned are from fat. With intensity levels higher than 72 percent, a larger percentage of calories burned come from carbohydrates. However, higher-intensity exercise requires more energy and leads to a greater calorie expenditure for a given period of time than less-intense aerobic exercise. Though exercising at a higher-intensity level burns more total calories, it can be more difficult to maintain for longer durations.

Recommendations

The basic recommendation for achieving health benefits is 30 minutes of moderate-intensity aerobic exercise five days a week, or 20 minutes of vigorous-intensity exercise three days a week, according to the American College of Sports Medicine. If your goal is to burn fat while maintaining muscle tissue, long-duration exercise lasting 30 to 60 minutes is recommended, but exercising longer than 60 minutes can result in the body using muscle tissue for energy instead of fat or carbs, says Bob Cicherillo, IFBB professional bodybuilder. However, using a combination of both short- and long-duration aerobic exercise in your fitness program may be the most beneficial in achieving overall health benefits.