A woman in a gym, apparently having just completed a workout, says, "Fast: that's just the kind of relief my muscles need." Or something like that. It was the beginning of a commercial, and don't ask me for what (other than some pain relief drug, obviously) since it was switched off after that line. Perhaps it was a good commercial, though, since it did get me thinking.
First of all, why is she sore immediately after working out? Sounds like she needs a new workout. (Or a good trainer!) Immediately after a hard workout, muscles experience fatigue, often in the extreme. As in "I can't get up" extreme. But that's different from pain, and no pain-relief product will put a stop to that. The muscular pain associated with a hard workout typically shows up 24-48 hours afterwards and is known as Delayed Onset Muscle Soreness or DOMS.