gary: hey, why are you eating that humungous slice of cake?  noel: i'm just finishing off my calorie-neutral run
a run (or other form of exercise) at the end of which cake is eaten, leading to neither a net loss nor net increase of calories
"gary: hey, why are you eating that humungous slice of cake?  noel: i'm just finishing off my calorie-neutral run" What is the definition of "calorie-neutral run"?