Time! Sore muscles, especially those from a hard workout or a new strenuous activity, simply recover on their own. Soreness should resolve within 3-4 days. Hydrating well, applying ice and/or heat for 20 minutes 2-3x/day and resting the muscles until the soreness has significantly reduced should suffice for most. Nsaids like advil or Aleve (naproxen) can be used for a few days to alleviate the soreness.