I recall a professional bodybuilder saying that drinking a solution of sodium bicarbonate helped neutralize the lactic acid buildup in tissue. That seems a bit rough, but the chemistry is at least right. Aspirin is another acid, and analgesic properties aside, I would think consuming more acid would compound the problem.
A nice hot jacuzzi seems to do wonders for me when I am that sore. Stretching keeps me limber, but doesn't do anything for the pain. If I am in real distress, I find a good deep tissue massage therapist and let them work on me as much as I can stand.
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The ultimate result of shielding men from the effects of folly is to fill the world with fools.
-- Herbert Spencer, English Philosopher (1820-1903)