Try it. neuropharmologically, there may be no specific "scientific data" to support the claim that endorphins are released from working out.
But let's consider this logic for a moment - what does is the body's natural response to pain? Why, painkillers!
And what are painkillers? Endorphins. All opiates/oids really are are an imitation of the body's natural response to pain, releasing the endorphins that would have already been released from some sort of physical exercise.
Maybe not neuropharmological logic, backed by scientists laboring away behind computers and studying rats, but it's just plain fucking OBVIOUS logic.
Like I have said numerous times throughout this post, go work out, and see how you feel. tell me if you feel like you're tweaking, high on marijuana, or if you just ate about 15-20 of vicodin (depending on the degree of your workout).
Of course, this challenge requires you get off your (no assumptions, just for comic relief mind you

) lazy ass and go work out. I double dog dare you.