If you want to lose a single pound of weight by exercise alone, you'll need to get quite a bit of exercise. You'll also need to make sure you don't eat more than you usually would or you’ll need to get even more exercise. How much exercise you need to lose one pound depends on your weight, the exercise you choose and how vigorously you work out.
Calories to Lose One Pound
To lose one pound of body weight, you'll need to burn an extra 3,500 calories. So to lose one pound a week, you could aim to do a daily workout that burns about 500 calories. Burning about 1,000 extra calories per day through exercise would help you lose about two pounds per week. Losing weight and limiting the risk of regaining this weight often requires at least an hour of exercise per day, according to the American Council on Exercise.
Intensity Affects Calories Burned Through Exercise
The more vigorously you exercise, the more calories you’ll burn. Dancing, calisthenics, walking at 4 miles per hour and mowing the lawn while pushing a power mower, all burn about the same number of calories per minute. These are all relatively moderate-intensity exercises. You'll burn twice as many calories per minute by running at 6 miles per hour, because of running's increased intensity level. Jumping rope, doing taekwondo or high-impact step aerobics, cycling at least 16 miles an hour, playing handball and swimming laps vigorously are among the better ways to burn a lot of calories quickly through exercise.
For example, someone who weighs 125 pounds burns 600 calories an hour doing high-impact step aerobics; a 155-pound person burns 744 calories per hour; and a 185-pound person burns 888 pounds per hour. On the other hand, walking at 4 miles per hour only burns 270 calories per hour for a 125-pound person; 334 calories per hour for a 155-pound person; and 400 calories per hour for a 185-pound person.
The Effect of Weight on Calories Burned Through Exercise
The more you weigh, the more calories it takes for you to do a particular exercise, so heavier people burn more calories in the same amount of time than lighter individuals. For example, a 185-pound person would burn 532 calories in an hour of using the stair stepper machine or by doing vigorous weight lifting, but a 155-pound person would only burn 446 calories and a 125-pound person would only burn 360 calories. Thus, a 185-pound person would need to exercise for an hour a day for about seven days to lose one pound doing one of these exercises, but it would take the 125-pound person about 10 days of exercising for an hour a day.
Playing handball or bicycling at 16 miles per hour would burn about the same number of calories in about half the time, but it would take about twice as long to burn these calories if you choose to get your exercise by playing Frisbee, bowling, playing water volleyball or by slow dancing.
Effectiveness of Exercise for Weight Loss
Typically, exercise on its own isn't very effective for weight loss. Only about 1 percent of study participants on the National Weight Control Registry who lost weight and kept it off for at least a year did so through exercise alone. An article published in Obesity Reviews in 2013 notes that people tend to lose less weight than predicted through exercise, mostly because people don't exercise as much as they need to and may compensate for the increased exercise by eating more or by getting less non-exercise activity, thus minimizing the calorie deficit they're creating.
A Better Alternative
A study published in Systematic Reviews in 2014 found that a combination of diet and exercise was best for weight loss and that dieting was more effective than exercising for people who opt to use only one of these methods. Another study, published in the Journal of the Academy of Nutrition and Dietetics the same year, had similar results, noting that in the short term, dieting alone and dieting plus exercise appeared to be about equally effective -- but in the long term, the combination of diet and exercise yielded better results. So you may be better off trying to cut 500 calories from your diet each day, along with getting about an hour of aerobic exercise. Don't forget strength training, as this can increase muscle mass and metabolism so you'll burn more calories, even when you aren't exercising. Try to fit in at least two strength-training workouts per week, including a number of exercises to target all major muscle groups.