The first time back to the gym after a long break usually results in sore muscles. Fortunately, the return trip a few days later--if it happens--is generally less painful. Scientists have studied this reduced-soreness phenomenon for decades and even have a name for it--the repeated bout effect. Despite all those years of research, they still can't figure out exactly why people feel less sore the second time around. What they do know is the immune system plays some role in how the muscle repairs![]()
