If I eat 1500 calories a day and then burn 500 off by cardio, is that the same as only eating 1000 calories for the whole day? And if so does that mean my metabolism will slow down?
The answer is yes and no. In the short the equation works out to the same answer. However, when you eat 1500 and burn 500 in cardio you have the added benefit of increasing your body's metabolism, improving your cardiac health, releasing endorphins (body's natural feel good drugs), and eating that extra 500 calories. The other way you will eventually slow down your metaboism, and miss out on eating that extra 500.