can someone tell me what causes muscle pain.
last sunday i went on a six hour hike, very hilly. monday morning my quads really ached walking down stairs. i then went on a very hilly 2 hour run off road, i thought it might ease the muscles but it didn't. i realise the pain/ache is caused by overuse, but what actualy happens to the muscles are they damaged, and what is the best cure, rest or stretching.