Why does the body feel sore after a work out? Stretching is done already & water is taken as well. And why does is it have to be so painful??

Exercising muscles. tears the fibers and produces lactic acid which pools in the belly of muscles. This causes some pain. Yes, stretching and a cool down walk can be most helpful to remove the lactic acid via circulation. Please see your doc to make sure everything is ok. Peace and good health.