Does Walking Or Sprinting Burn More Fat?

Bodybuilders have debated for years, which is the most effective form of exercise to burn fat. Older bodybuilders who used low-intensity long-steady state cardio such as walking or biking to burn fat, still claim that it is the best way to lose fat and preserve muscle tissue. Newer bodybuilders prefer doing more sprints and high-intensity interval training or HIIT into their training programs to burn fat. However, both training styles burn fat in different ways, and depending on your training goals, you may benefit from include both in your program.

Low Intensity Cardio

Low Intensity cardio such as walking burns a larger percentage of total calories from fat than high-intensity cardio. When your heart rate consistently stays within the peak fat burning, between 55 percent and 72 percent of your maximum heart rate, a majority of the total calories burned will come from fat stores instead of carbohydrates, notes Jack H. Wilmore and David L. Costill, authors of "Physiology of Sport and Exercise." In the initial stages of aerobic exercise, carbohydrates become the number one fuel source. After a few minutes of doing consistent low intensity cardio, your body will start using fat stores as its primary energy source. Ideally, low- to moderate-intensity cardio should be performed for 30 to 60 minutes. Cardio performed longer than 60 minutes may resort to burning protein sources or muscle tissue for energy, because your body senses it is going to extremes and will attempt to conserve fat, notes Bob Cicherillo, IFBB Pro Bodybuilder.

High Intensity Cardio

Exercising at a higher intensity level, 75 percent or more of your maximum heart rate, your body will burn a larger percentage of calories from carbohydrate sources, instead of fat stores. However, high-intensity exercise burns more total calories than low-intensity exercise in the same amount of time. Sprinting or HIIT has an effect on your metabolism by not only burning calories during the activity, but also keeping your metabolism elevated longer after your workout, which helps you burn more total calories. Furthermore, exercise performed at a higher intensity in less time, not only helps preserve muscle tissue, but can also help you build muscle mass, notes Jim Stoppani, Ph.D.

Fat Burning Program

Sprint workouts are demanding on the body and may not be suitable for people who are new to exercise. Beginners should start with performing 30 minutes of brisk walking five days a week. Once you have been consistently able to complete at least 30 consecutive minutes of moderate-intensity aerobic exercise, gradually replace moderate-intensity cardio sessions with high-intensity session, up to three a week on nonconsecutive days.

Energy Expenditure

The faster or more intense an activity is, the more calories are required to fuel the activity. Furthermore, the more you weigh, the more the energy will also be required to fuel the activity. In other words, a heavier person walking, running or sprinting at the same speed as smaller, lighter person, will burn more calories than a lighter person. For example, a 140-lb. person will burn about 4 calories per minute exercising at 3 mph, 5.2 cal/min at 4 mph, 11.8 cal/min at 6.8 mph and 17.0 cal/min at 10 mph. A 200-lb. person will burn about 5.3 cal/min at 3 mph, 7.0 cal/min at 4 mph, 15.6 cal/min at 6.8 mph and 20 cal/min at 10 mph.