To lose one pound of fat, you must burn 3,500 calories more than you consume. If you've ever paid attention to the number of calories you burn during an easy cardio workout, like walking on the treadmill for 30 minutes, the idea of creating a 3,500 deficit may seem a little overwhelming. At the same time, television shows like "The Biggest Loser" and "Extreme Makeover Weight Loss Edition" feature contestants who experience incredible weight loss week after week, suggesting that burning 3,000 calories in one day from exercise is indeed possible. However, there are a few realities you must understand before you set out with such an extreme goal.
You've got to take your current weight and condition into consideration when estimating potential calorie burn through exercise. Someone who weighs 300 pounds and is out of shape will burn far more calories than a lean, 150-pound person who exercises regularly. For example, according to a calories burned calculator provided by the American Council on Exercise, a 300-pound person would burn 1,428 calories during one hour of moderately intense rowing, while a 150-pound person would burn 714. Extreme endurance athletes, such as Ironman competitors, ultramarathon runners and Olympic athletes, can easily burn 3,000 calories a day from exercise, but these are people who are able to devote several hours each day to training. For the average exerciser, a goal of 3,000 calories a day may be unrealistic. Instead of relying solely on exercise, shoot for a daily deficit of about 1,000 through a combination of diet and exercise, for safe, attainable weight loss.