Because calories equals about 1 pound kilogram) of fat, you need to burn calories more than you take in to lose 1 pound. So, in general, if you cut 500 calories from your typical diet each day, you'd lose about 1 pound a week calories x 7 days = calories)
eaten-away: More jumpin jacks fo me I keep seeing this, and the math makes no sense. If every two jumping jacks burn 1 calorie, than 1000 jumping jacks would burn 500 calories. Not 3500. Not a pound of weight. However, jumping jacks are still awesome. Easy to do and get your heart rate up quickly. I do 100-300 a day, spread throughout the day.