When you’re hurting, it’s natural to want to do something about the pain.
So after an intense workout — the sort that leaves your body aching — many of us reach for an over-the-counter painkiller like ibuprofen (Advil) or naproxen (Aleve).
These drugs, called nonsteroidal anti-inflammatory drugs (NSAIDs), do effectively reduce inflammation, which is what makes them effective at treating certain types of pain. But according to a study recently published in the journal Proceedings of the National Academy of Sciences, when taken after exercise the drugs also seem to dampen the muscle growth effect provided by exercise.
If your goal is to get stronger, trying to eliminate the pain with drugs may make the workout less effective.
In the most recent study, researchers took a look at injured muscle tissue in mice. Without intervention, the mice would generate compounds known as prostaglandins that stimulate muscle stem cells and regeneration, or healing. But NSAIDs blocked the production of those prostaglandins. Those mice didn’t generate as many muscle stem cells or heal as much as they would have otherwise.
Mice aren’t people, so one study alone should be taken with a grain of salt. But there’s other research with similar findings.
Other studies in mice have shown that ibuprofen cancels out some of the skeletal muscle growth that would normally happen after distance running.
And in humans, researchers have found that both ibuprofen and acetaminophen (another type of pain reliever, often branded as Tylenol) suppress the protein formation that occurs in muscles after high-intensity exercise. Even more research has found that nonsteroidal anti-inflammatory drugs like ibuprofen (aspirin is also in this category) inhibit bone healing. There’s even some evidence showing that using ibuprofen regularly for soreness may damage cellular tissue and generally prevent your body from even being able to take full advantage of exercise.
How healing works
Inflammation hurts, but it kickstarts the physical adaption process that makes you more able to handle damaging physical stress in the future.
Some research has found that certain pro-inflammatory compounds produced by exercise trigger the release of powerful anti-inflammatory substances that help damaged muscles heal and have other long-lasting health benefits. Artificially suppressing the initial inflammation could prevent that healing process, neutralising some of the real benefits of exercise.
Plus, there are other reasons why over-the-counter painkillers, which most people think of as safe enough to take on just about any occasion, are far more dangerous than we think. The FDA warns they can raise the risk of heart attack or stroke, even in patients without heart disease. They’re also linked with stomach bleeding and ulcers. Acetaminophen, a common non-NSAID painkiller, can cause permanent liver damage and sends tens of thousands of people to the emergency room every year.
For some injuries, these drugs are the best choices. But just because they’re available over-the-counter doesn’t mean they should be taken freely for injuries or soreness. If your doctor recommends them, that’s one thing.
But if you’re just sore from a workout, take pleasure in knowing that your body is healing.
Business Insider Emails & Alerts
Site highlights each day to your inbox.