The intensity (effort) of your workout is important. Some previous studies of low-intensity workouts–like strolling around the block–had shown that they produce little to no EPOC. Nieman says you have to work hard enough to break into a good sweat. Or, more technically, he notes that you have to produce a “homeostatic disturbance.”
Interesting article on “afterburn” and how to get the most benefit out of it. Afterburn is used to describe the process where the body keeps burning calories even after we’ve stopped exercising.
This article suggests that increasing the intensity of a run will increase the afterburn effect.