DO AEROBICS OR ISOMETRICS BURN FAT FASTER?

By Christina Schnell

Open any fitness or fashion magazine and you'll see supplements, machines and diets promising to help you burn more fat. Regular exercise is one of the best ways to keep fit, but the variety of exercise methods can be daunting. Determining which type of exercise burns the most fat requires an understanding of the individual methods, along with basic knowledge of how your body burns fat.

Fat-Burning Basics

Your body converts the calories you don’t burn into fat. When you perform any type of exercise, your body’s first source of energy includes the calories you most recently ate. Burning through this first source of energy entirely forces your body to convert fat from your fat cells back into energy. Using fat stores for energy lowers your total percentage of body fat by shrinking the size of your fat cells. In other words, you must burn calories before tapping into your fat reserves.

Aerobic Exercise

Aerobic exercise is a form of cardiovascular fitness that raises your heart rate by pumping blood through your entire body. The intensity of cardiovascular activity can range from 60 to 80 percent of your maximum heart rate, although your age determines the exact range of your heart rate. Examples of aerobic activity include running, biking and swimming. Intense aerobic activities that engage large muscle groups, such as running, burn more calories than low-intensity activities like walking.

Isometric Exercises

Unlike aerobic activity, isometric exercises focus on building muscle strength by contracting an isolated group of muscles without stretching the tissue fibers through a wide range of motion, such as a squat or a lunge. For instance, pushing against a wall or holding a heavy bar above your head without moving are both isometric exercises. Rehabilitation and physical therapy techniques use isometric exercises because they don’t strain joints or tendons.

Maximizing Your Fat-Burning Exercise

The amount of calories you burn increases with the intensity and duration of your activity. Aerobic exercise uses multiple muscle groups, which increases the number of calories you burn. In contrast, isometric exercises work only one or two muscles, which burns fewer calories. Because burning calories is the only way to begin burning fat, regular aerobic activity is more efficient than isometric exercises for losing weight. Adjusting your diet so you're eating fewer calories than you're expending is also critical for burning fat.

References

• MayoClinic.com: Aerobic Exercise -- Top 10 Reasons to Get Physical
• MayoClinic.com: Are Isometric Exercises a Good Way to Build Strength?
• MayoClinic.com: When You Lose Weight, Where Does the Lost Body Fat Go?
• Columbia University: Go Ask Alice -- Minimum and Maximum Heart Rate During Cardiovascular Exercise