Eating back burned calories.

Exercise has a multitude of benefits beyond just burning calories. Weight bearing exercise helps to retain lean muscle mass on a caloric deficit. Exercise reduces visceral body fat, the kind associated with metabolic disorders like heart disease and diabetes. Cardio exercise lowers your glucose numbers for 24-48 hours after doing it. It has positive effects on mentsl health. It has long term positive effects on most biomarkers even if you don't lose weight. It's actually healthier to be obese and significantly active than it is to be thin and sedentary.

Also some people like to exercise just so they can eat more and still lose or maintain weight.

This thread explains it perfectly

http://community.myfitnesspal.com/en/discussion/818082/exercise-calories-again-wtf/p1

To me, if you want to lose weight, you need to consume less calories than you burn. If you exercise, you can eat more and still lose weight. It's a nice thing.

But if you want to be fit, you need to exercise. I would argue that people should exercise not to lose weight, but to be fit. Exercising to lose weight is too much of an effort compared to reducing the amount of food you eat, and in my opinion is not as effective. Combining dieting and exercise is very very very effective though.

MFP gave me 1200 calories. I can't live on 1200 calories. So I exercise & eat them back. If I don't eat them back I get dizzy which certainly isn't helpful