Yesterday my friend posted her status on Facebook, shocked that she hadn't burnt more calories running for a short time mixed with some fast walking. I found a great article on hungry girl about our misconceptions of calorie burn. very interesting, read on...........
We're not saying you should avoid excercise in order to lose weight (sorry lazy people!) But the truth is, research shows that people grossly overestimate how many calories they burn during excercise. Not only that, but physical activity often makes people hungry. And since we tend to think we burned more calories than we really have, we can end up consuming MORE calories than we've burned. Remember, it all comes down to calories in vs. calories burned. So don't use a workout as an excuse to pig out. Be realistic about how many calories you are burning while excercising. Use the data provided on the cardio machine if you have entered all your info (without lying to the machine!!!) Or check out online resources to get a good idea of the effect your workout is actually having on your calorie balance. Then you can make adjustments to make sure your workouts help you achieve your goals!
ps- I personally use livestrong.com to track my calories in vs calories burned. They will even let you know the exact number to eat to lose X amount per week or to stay steady in your current weight. Also will tell you how much you burned during any given excercise. Its a great site!