The sensation, due to extremely strenuous exercise, when one's muscles temporarily stop burning and the entire limb starts pulsing in a rhythmical and sadistically pleasurable fashion.
"Oh man, I had a massive lactate orgasm in the last 500 of that ergo."

"I was bashing out 2x10 Miles on the bike and totally had a lactate orgasm in the second one."
by SkyWatchFarmer June 4, 2012
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