For some, feeling sore after a workout is a badge of honor: They’re proud to have pushed themselves to the limit. But new research suggests that overexertion makes you temporarily weaker and puts you at risk for injuries.
Delayed onset muscle soreness (DOMS), the pain you feel one or two days after exercise, occurs when damage causes overworked muscle fibers to leak certain proteins and enzymes into the blood, says Jerrold Petrofsky, PhD, professor of physical therapy and director of the research laboratories for the School of Allied Health at Loma Linda University in California. Although the muscle impairment heals on its own in two to 10 days, the affected muscles may lose up to 30 percent of their strength in the interim. This weakness sets you up for further damage. For instance, a 2011 study in Medicine & Science in Sports & Exercise found that DOMS-affected quadriceps muscles displayed a reduced ability to stabilize the knee during exercise, upping the odds that the joint will get injured.
So how sore is too sore? Mild pain is OK, says Petrofsky, but when you can’t go about your daily activities, you’ve overdone it. If that’s the case, apply heat packs to your aching muscles—studies show this can speed recovery—but don’t return to your regular exercise routine. Instead, perform light workouts, such as slow walking, to promote a healthy range of motion and circulation until the pain subsides. When you resume your normal regimen, scale it back at first. And try to treat your body more gently in the future. “If you follow a routine that increases the intensity of exercise slowly, you shouldn’t get sore,” says Petrofsky. “You can get stronger without damaging your muscles.”