Yea, we know—it burns! But the future you will thank you
"No pain, no gain" applies to more than just working hard to tone those gorgeous muscles. Embracing the pain of a serious sweat sesh can actually increase your pain tolerance, says a new study in the journal Pain.
When researchers from the University of Manchester took brain scans of volunteers, they discovered that people who experienced chronic pain had more opiate receptors in their brains than the pain-free participants. Opiate receptors bind with endorphins—the feel-good hormones your body produces when you do something physically hard—so the more of these receptors you have, the more of that post-workout high you get to feel. (That might explain why Runner's High Is As Strong As a Drug High.)
The researchers believe the number of natural painkilling receptors actually increases to help you cope with long-term pain, which means the better you learn to endure pain, the less pain you'll feel. While the study is small and more research needs to be done, the findings are still exciting.
How this translates to your workouts is pretty simple, says Andrew Cosgarea, M.D., Chief of Sports Medicine at John Hopkins in Baltimore. On a very basic level, you have to be able to tolerate some pain during exercise to see any results—as anyone who's ever powered through a grueling weight lifting session knows.
"For strength to increase, the muscle must feel some increase in stress, usually perceived as 'the burn.' This mild burn is what we call 'good pain,'" he explains. The more often you work inside this "burn" range, the less heavy weights will hurt and the more reps you'll be able to do. It's important, he adds, not to give up at the first sign of discomfort. Combining the good pain from a workout with the endorphin rush that naturally comes with exercise could be the magic combination for learning to truly love fitness.
But while some pain during your workout is good, more is definitely not better. Overdoing your gym sessions can lead to exhaustion and injuries, leading to more pain, not less, he says. Muscles, tendons, ligaments, cartilage, and bones are living structures that react to the stress of exercise very slowly, Cosgarea explains. "If they see stress too fast or too much over time, they begin to fail, which is what causes bad pain" he says. (Learn 5 Times You're Prone to Sports Injuries.)
How do you know when you've crossed the line from good to bad pain? Healthy pain should only last as long as you are doing the activity, Cosgarea says. A little soreness post-workout is fine, but if you're chronically having severe muscle pain to the point where it's limiting your daily activities outside the gym, then you've pushed too hard. (Shocked at how sore you are? Find out Why Post-Workout Muscle Soreness Hits People at Different Times.)
So the next time you're seeing stars while you sprint or feel your muscles shaking while you eke out those last few curls, know that powering through can actually help you push harder on your next workout.