Why Is High-Intensity Exercise Better for Weight Loss?


High-intensity forms of exercise, such as jogging or lap swimming, burn more calories than moderate forms of exercise like walking or gardening. This makes these high-intensity workouts a more efficient way to lose weight. High-intensity exercise, coupled with a diet that reduces your consumption of calories, is the fastest and most reliable way to both lose weight and keep the weight off, according to the Centers for Disease Control and Prevention.

Moderate vs. Vigorous Exercise

Because so many people are sedentary, many exercise programs recommend people start with “moderate” exercise, like walking, for weight loss. But it takes much longer to burn calories walking than jogging; you have to walk up to two hours at 3.5 miles per hour to burn as many calories as jogging for an hour at 5 mph (590 calories), the CDC says. The American College of Sports Medicine now actively encourages that vigorous-intensity workouts be a part of any workout regimen because of the “substantial science base” showing how beneficial it can be. A 2003 study at the University of Pittsburgh found that overweight, sedentary women who exercised vigorously for 60 minutes every day for a year lost 20 pounds, while the women who exercised moderately for 30 minutes a day lost only 14 pounds.

How to Know if Your Exercise is Intense Enough

The simplest way to measure your effort is by how hard you are breathing. According to exercise experts at the University of Maryland, if you can talk easily during a workout, you need to exercise harder. If you can converse but your sentences are clipped because you’re breathing hard, you are exercising at the correct intensity. If it’s hard to say anything, you might be exercising too hard. Another way is to figure out your maximum heart rate (220 minus your age) and exercise at 60 to 70 percent of that number.

How Much High-Intensity Exercise Do I Need to Lose Weight?

To lose a pound a week–several studies have found that if you lose more than 1 to 2 pounds a week you are more likely to gain the weight back–you have to either cut back on 3,500 calories a week, burn up 3,500 calories or do a little bit of both to reach the magical 3,500-calorie mark. For overall cardiovascular health, the CDC recommends 150 minutes a week of moderate exercise or 75 minutes of high-intensity exercise. The American College of Sports Medicine recommends up to 300 minutes a week of exercise.

What Are the Best High-Intensity Exercises?

The best calorie burners include jogging, lap swimming, cycling and cross-country skiing. Many exercise machines–such as stair machines and elliptical trainers–can provide high-intensity workouts if you use them correctly. Calories burned while cycling depend on your speed–cycling at less than 10 mph burns about 300 calories an hour while cycling faster than 10 mph burns nearly 600 per hour. Cycling up big hills burns calories even faster.

Is Vigorous Aerobic Conditioning Enough?

When the American College of Sports Medicine (ACSM) issued its first fitness guidelines in 1978, it called for three to five aerobic exercise sessions a week of 20 to 60 minutes each. When those guidelines were revised, the ACSM kept its aerobic recommendations but added two to three sessions of “resistance training”–such as push-ups and weightlifting. This type of exercise also burns calories and helps reduce body fat. But the muscles you gain may increase your weight because muscle weighs more than fat.

Additional Weight-Loss Benefits Come From Vigorous Exercise

According to the ASCM and the American Heart Association, high-intensity exercise helps weight loss in ways that can’t be simply calculated. For instance, trained muscles, even at rest, burn more energy, and that expends calories. Working muscles also have to be restocked with glycogen after the exercise is over, and that metabolic process burns calories, too. It’s also been shown that exercise improves a person’s discipline, making them less likely to eat fatty foods that cause them to gain weight.

About this Author

Jim Sloan is a writer and editor in Reno, Nevada. He has been a journalist for more than 25 years and is the author of two books, “Staying Fit After Fifty,” and “Nevada: True Tales from the Neon Wilderness.”