One lb. of fat is equivalent to 3,500 calories. The National Institutes of Health reports that to lose 1 lb. a week, you should either consume 500 fewer calories a day or burn 500 calories a day. To burn 2 lbs. a day, you would need to burn 7,000 calories, a feat that would even be difficult for an Olympic athlete.
To burn 7,000 calories a day you would need to exercise for several hours. A 160-lb. person would burn 511 calories after one hour of high-impact aerobics, 584 calories after a 60-minute basketball game and 292 calories after a one-hour, 10 mph bicycle ride. At that point, after three hours of high-intensity exercise, you will have only burned 1,397 calories, less than half of your goal. It would take one hour of Frisbee playing to burn 221 calories, one hour of lifting weights to burn 250 calories, an hour of hiking to burn 432 calories, an hour of jumping jacks to burn 586 calories and a 60-minute touch football game to burn 634 calories. After eight hours, and 3,510 calories, you will have only burned 1 lb.
If you're going to attempt to burn 2 lbs. a day, you will need to consume plenty of calories to feed all that energy. Olympic gold medal swimmer Michael Phelps consumes an estimated 12,000 calories a day when training. According to the Wall Street Journal, Phelps exercises five hours a day, six days a week, when preparing for competition. The American Heart Association reports that active women require 2,200 to 2,400 calories a day and active men require 2,400 to 3,000 each day. Active is characterized by having a physically active lifestyle equivalent to walking more than 3 miles a day at 3 to 4 mph, in addition to your regular daily routine. Active, as defined by the AHA, does not even closely define the exercise regimen of a person whose aim it is to drop 2 lbs. a day.
Unhealthy Ways to Lose Weight
It's not healthy to lose weight too quickly. The American Academy of Family Physicians report that if you lose more than 2 lbs. a week, you may just be dropping water weight and burning off lean muscle mass instead of fat. You won't have much energy to exercise and you're likely to gain that weight right back. Eating too few calories won't help you reach your weight-loss goal of 2 lbs. a day, either. The University of Florida Extension Institute of Food and Agricultural Sciences reports that women require at least 1,200 calories a day and males need at least 1,600 calories a day. Eating too few calories can lead to malnutrition in the short run and chronic conditions, such as osteoporosis, in the long run.
Healthy Ways to Lose Weight
The healthiest way to lose weight is to exercise regularly and control your calorie intake. The American College of Sports Medicine recommends getting 30 minutes of cardiovascular exercise five days a week as well as doing eight to 10 strength-training exercises two days a week. If you burn more calories than you take in and exercise often, you could drop 8 lbs. within a month.