Science or bro-science?

Is physical therapy backed by hard science or artisanry?

Last week in the Washington Post, fitness columnist Gretchen Reynolds wrote about a “new way to treat sprains.” The common, catchy advice of RICE (Rest, Ice, Compression, and Elevation) was out, and new science had come to light: Doctors and scientists now concur with youth sports coaches that you should “walk it off.”

I’m barely being glib. Reynolds quoted research suggesting that reducing inflammation impairs the body’s natural healing mechanisms. By damping inflammation, scientists conjecture you are damping regeneration. This means that anti-inflammatory drugs like ibuprofen are also counterproductive, as they suppress key pathways that aid the healing process. Moreover, resting leads to muscular atrophy and loss of strength in tendons and ligaments. Putting it all together, rest and anti-inflammatory therapies compound to impede healing.

Reynolds cites expert studies on this topic (there are always studies), but to someone immersed in the culture of bro-science, I was surprised this advice was considered new and novel. Since getting a bit too obsessed with strength sports, I have injured myself multiple times, and I have never visited a physical therapist or watched a fitness YouTuber who recommends resting after an injury. Instead, most tell you to move as much as possible and to reduce inflammation only if it’s getting in the way of that movement. If you get injured, they advise you not to panic, to find what motion gets you moving, and to exercise around the limitations brought on by the injury. The place you sprained will be mobility-restricted, but you should access as much range as you can and keep things light, slowly adding work back as you go.

The working model that coaches and PTs share is that weight training and injury recovery are both processes for getting stronger. An injury is just a disadvantaged starting point. In both cases, the way to increase strength is to regularly stress the system with increasingly harder tasks. Every time, you hope to access more range or lift more weight. This is the principle of progressive overload.

Though now the backbone of most sports training and fitness programs, progressive overload originates in physical therapy. The common prescription of “three sets of ten” originates in the practice of physician Thomas DeLorme, who worked to rehab injured soldiers during World War II. His plan to heal, borne out by diligent clinical practice, became the foundation of the modern paradigm for getting stronger.

Though DeLorme’s progressive overload principle worked wonders in patients and athletes alike, standard medical practice unfortunately always needs a stamp of “science” to back it up and make it real. The practice of coaches, trainers, and physical therapists everywhere can’t justify a technique. That’s bro-science. You need some obscure microbiological pathway or a randomized experiment.

The problem is, the science of physiology is much murkier than you might expect. For years, I have been looking for a clean mechanistic description of why bodies adapt to training. Why do we get stronger and faster by progressively working harder at the gym? Reynolds’ column quotes UC Davis Professor Keith Baar applying his research to his own ankle sprain. Baar has long studied the molecular biological pathways that explain why training techniques like progressive overload work and why bodies adapt to stress. He co-authored one of my favorite surveys on adaptation to training, which lays out the myriad biological pathways and how different sports modalities shape them. My main takeaway from the survey is that we still don’t have a clear, comprehensive description of how the body adapts to exercise. The experiments all agree that if you progressively overload, then you get better. There are lots of things you can measure in a body under stress that point to something mechanistic going on. But they can’t pin down a precise mechanism that drives adaptation, and they certainly can’t figure out what an optimal training protocol would look like. In sports medicine, we don’t follow the science. Science follows the practice.

Coming back to inflammation, we can look at the evidence that ibuprofen inhibits muscle growth in strength training. Common gym wisdom is that ibuprofen, those sugar-coated orange pills often consumed like candy by gym addicts, are actually killing your gains. Bros tell you that you have to tough out the delayed onset muscle soreness associated with training. This was also the conclusion conveyed by the scientists quoted in Reynolds’ article.

Well, the science is of course far less certain than the YouTube advice. I could only find one study showing that taking ibuprofen inhibits muscle hypertrophy when strength training. In this study of 31 people aged 18-35, the treatment group took 1.2 grams of ibuprofen every day for eight weeks, and the researchers observed that they had less muscle growth than the control group. 1.2 grams is the maximum recommended over-the-counter dosage! This is a bit extreme. And yet, despite multiple attempts, no study has ever reproduced these results. There’s a fun fight between one of the failed replication teams and the original authors if you’re into those sorts of academic spats.

So who knows, team? It’s possible ibuprofen doesn’t affect training performance at all. I personally wouldn’t recommend eating it like candy. But what do I know? I’m not a scientist.