Net Calories

Calories confuse me. I understand that I ate more calories than my body needed to sustain itself and so those extra calories were stored as fat. I understand that if I eat less calories than my body needs to sustain itself I will burn stored energy and I will weight. What I don't understand is the best way to decide how many calories to eat.

I love using Livestrong.com and their calorie counting tool- my plate. It even sets goals for you. I have success when I use it. BUT I am wondering if I am still doing something wrong. Right now my Caloric Goal is 1423 calories per day. That is based on my desire to lose 1.5 pounds per week. So when I do not exceed 1423 I have an automatic caloric debt of 4200 calories per week. But I am also training for a 10k and I am exercising 5-6 times per week, burning between 300 and 500 calories with each workout. So most days I have net calories of 923-1123. Is my body going to rebel against this? Do I need to eat those calories that I burned to get back up to the 1423? Should I at least say that I will always maintain a net caloric intake of at least 1200? I don't know and I have been reading on the Internet and no one says exactly what to do.

So I am toying with the idea of experimenting. Going for a week or two NOT re-eating the calories I burned and seeing what happens. Then taking a week or two and trying to always re-eat the calories burned, still never exceeding a net caloric intake of my current calorie goal. Who knows maybe I will discover that my body burns fat better one way or the other. I will definitely be telling you how it is going.