Numerous myths surround cardiovascular exercise and its ability to burn fat, such as, "You only burn fat when you exercise in the fat burning zone," and "You don't begin to burn fat until after 20 minutes into a workout." Instead of looking at cardio's ability to burn fat, shift your focus to how many calories it burns. Because a pound of fat equals about 3,500 calories, the more calories your cardio workouts burn, the more fat you'll lose. Boost the calorie burn by adding intensity and interval training.
Running delivers an effective fat-burning cardiovascular workout, but cycling, swimming, hiking, tennis and inline skating offer equivalent cardio benefits. But why limit yourself? Choose any other exercise performed at a high intensity with minimal rest for a potent fat-burning cardio workout.
Although walking provides a light to moderate cardiovascular workout that may keep you from gaining weight, you need greater intensity to lose weight, according to a study in the October 2005 issue of the Journal of Applied Physiology. Researchers from Duke University Medical Center studied overweight adults and found that only jogging 20 miles per week -- equivalent to four, one-hour workouts at a pace of five miles per hour -- burned belly fat when compared with a walking workout of only 12 miles per week -- equivalent to four one-hour workouts at a pace of three miles per hour. So, for the most effective cardio workout, step up your walk to a run.
The Journal of Applied Physiology published a study in its Dec. 7, 2006, issue indicating that the most effective fat-burning cardio exercise utilizes interval training. After two weeks of seven workouts, study participants' fat oxidation increased by 36 percent during exercise. Incorporate interval training into your workouts by sprinting for two to four minutes followed by a recovery period of equivalent duration. Do this for an hour every other day, and within two weeks your body will have increased its cardiovascular capacity and fat-burning ability.
To increase the effectiveness of your cardiovascular exercise, perform a circuit training workout. The Journal of Sports Science and Medicine published a study indicating that concurrent cardio and weight training resulted in a significant reduction in total calories consumed, about 500 each day.
The mythical "fat-burning zone" persists because of a kernel of scientific truth: Fat oxidation requires oxygen, which is available at lower intensities. However, when you're working above 75 percent of your maximum heart rate, your body receives energy from stored carbohydrates, according to the National Academy of Sports Medicine. Regardless of the source, burning energy creates a calorie deficit. The greater the deficit, the greater the fat stores used to replenish it.
About this Author
Pamela Ellgen is an award-winning journalist and certified personal trainer with the National Academy of Sports Medicine. She graduated with a B.A. from Washington State University where she studied writing. Ellgen wrote for the Portland, Ore.-based newspaper, "The Asian Reporter," for 10 years.
Read more: Effective Fat-Burning Cardio