Interval Training for Fat Loss
Many people mistakenly believe that the best way to lose weight through exercise is to train at a very slow pace for a long time. This notion came from Scandinavian studies conducted in the 1960s that showed that the body used more fat when exercising very slowly than when training more intensely. Some people interpreted these results to mean that low-intensity exercise is better for losing fat.
This notion is nonsense! You lose fat by burning more calories than you take in. You will burn many more calories training intensely than exercising slowly. The body does not metabolize fats by themselves. Rather, fat use is integrated with carbohydrate and protein metabolism. Even if you used more fat during exercise, fuel storage balances itself out according to energy balance — calories in versus calories out. Intense exercise causes you to burn more calories and fat after the exercise is over. So, when trying to lose fat, work harder and burn more calories.
What is Interval Training?
If you’re exercising to lose weight, adding interval training to your program will help you burn more calories. Interval training refers to bouts of higher intensity exercise interspersed with periods of lower intensity exercise or rest. Let’s say your current workout is a steady 45-minute spinning class in which you’re working at about 70 to 85 percent of maximum heart rate. If you introduce short periods of higher intensity sprints (at 80 to 100 percent of max) into the ride, you’ll do more work and burn more calories in the same amount of time. Also, you’ll rev up your metabolism so you continue burning calories even after you stop exercising. You can use interval training for all of your favorite aerobic exercises, including ground or treadmill running, stair climbers, elliptical trainers, swimming, or cycling.
There are also other benefits. Interval training also builds muscle power that will carry over to your fitness and body-shaping program. The strong, shapely muscles you build doing intervals will make it easier to do leg exercises such as lunges and squats and give you greater stamina that will help you better cope with your busy schedule. Intervals will also develop sleek, attractive lower body muscles faster and better than almost any other exercise.
Intervals can be a real time-saver, too. You know you need to run, work on the elliptical trainer, or ride a bike to cut fat, but you just can’t face the boredom of slogging along on the roads or looking at a blank wall for a half-hour— or, you just don’t have the time. Interval training not only makes you run faster, but also enhances cell enzymes that improve fuel use at rest and during exercise. Previously, scientists thought you needed to run for 45 minutes or more per workout to get these cellular effects. If you train intensely in short bouts, you can get more benefits in less time. An added benefit is that interval training turns up your metabolic furnace so you continue to burn more calories than normal all day long.
Components and Results
Interval training involves performing repeated exercises at set distances or times. This type of training helps the body move at faster speeds by training the nervous system to react more quickly, increasing the heart’s ability to pump blood, and help the cells cope with rapid metabolism.
The four components of interval training are distance, repetitions, intensity and rest. Distance refers to either the distance or time of the exercise interval. Repetition is the number of times the exercise is repeated. Intensity is the speed of the exercise. Rest is time between exercises.
Each factor of interval training is related to the others. When you train more intensely, you will do fewer repetitions and rest longer. For example, a runner performing 400-meter runs at 100 percent of her maximum running speed might only manage four to six repetitions. A woman working at only 75 percent of maximum intensity might manage eight to 15 repetitions.
Don’t practice interval training more than three days per week. Intervals are exhausting and can easily lead to injury. Let your body tell you how many days you can tolerate. If you are overtired doing three days per week, cut back to one or two days. Also, if you feel good, try increasing the intensity or volume and see what happens. Begin slowly and progress conservatively. Integrate interval training into your total exercise program. You shouldn’t be so tired from doing intervals that you can’t function during the day, or do other parts of your exercise and shaping program.
Intervals on the Treadmill
The treadmill is the best health club machine for burning calories and cutting fat— it’s better than ski machines, stairclimbers, stationary bikes and elliptical trainers. Interval training on the treadmill involves alternating between fast and slow running and walking. You can also vary the exercise intensity by raising and lowering the treadmill grade. Use the built-in programmer— if available— because it will automatically change the speed and elevation of the treadmill during your workout.
For treadmill walking, begin by exercising at a brisk pace that you can manage easily. For example, set the treadmill speed at three miles per hour and the elevation at a zero percent grade, and walk for two minutes. Then, raise the elevation to 10 percent and walk for one minute. Return to a zero percent grade and walk for another minute. Alternate each minute between walking up zero percent and 10 percent grades for a total of 10 minutes. As you become more fit, extend the total time or your interval training workout or increase the speed or elevation of the treadmill.
You can practice interval training in almost every sport and exercise. For example, in tennis, you could hit against a wall or tennis ball machine for two minutes, rest one minute, then repeat. On the stationary or supine bike, exercise for one minute at a high power output, rest one minute, then repeat. In basketball, you could run four court lengths, shooting a lay-up at each end, rest, then repeat. You are limited only by your imagination when setting up interval training programs. The bottom line is that interval training is a terrific fat burner and fitness builder that will help you make rapid progress.
Billat, L. V. Interval training for performance: a scientific and empirical practice. Sports Med. 31: 75-89, 2001.
Fahey, T.D. Superfitness for Sports, Performance, and Health. Boston: Allyn and Bacon, 2000.