eh.. That's why I think he's confused. It doesn't exactly work that way. If you eat an extra 500 calories, you're going to be hard-pressed to actually burn an extra 500 calories on top of that.
Let's say that I have a BMR of 1500 calories, and with my activity level, it goes up to 2000 even. Let's assume, then, that I unconsciously also eat at maintenance and very rarely stray from that. Now, being an active person, all the activity that I do for the week is accounted into the caloric expenditure expected for said week. Now, we take one day where I eat 2500kcal instead of 2000. Here's where we have an issue.
Let's assume that I do a work-out that burns 500 calories, and that took an hour out of my day. Let's say that it was an hour on top of what I normally do, so I'm pretty effin exhausted at this point. But let's also take into account how much I would have burned in that hour on a normal day (for the sake of ease, 2000/24 = 83.3.. if we skewer toward burning less while sleeping/more when we're awake, we'll just round up to 100). Now we're left with only a 400kcal expenditure on top of what is normal.
We're not even taking into account that, in most cases, doing extra activity that is abnormal normally results in being more lethargic/inactive at other times during the day, which would decrease it even further.
Basically, what it comes down to is that it isn't quite that cut and dry. In most cases, overeating and training doesn't let you come out even. And most people don't justify their food with extra activity, anyhow. They justify it with the activity they would have done (or should have done) regardless.
