Tag: recovery

THANK YOU FOR VISITING SWEATSCIENCE.COM!

My new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Also check out my new book, THE EXPLORER'S GENE: Why We Seek Big Challenges, New Flavors, and the Blank Spots on the Map, published in March 2025.

- Alex Hutchinson (@sweatscience)

***

Very cool new study on massage, from Mark Tarnopolsky’s group at McMaster (abstract here, press release here). Massage is one of those interventions that’s very difficult to study objectively — people like the feel of massage, you can’t blind them, and the outcomes you’re interested in are usually very subjective. But this study does a very good job.

The details: 11 volunteers exercised to exhaustion (about an hour or more on an exercise bike with gradually increasing pace) to induce muscle damage. Then, after a 10-minute break, one of their legs was massaged as follows:

(i) 2 min of effleurage, a light stroking technique delivered with a moderate pressure; (ii) 3 min of petrissage, a firm motion involving compression and subsequent pressure release from the muscle; (iii) 3 min of slow muscle stripping, consisting of repeated longitudinal strokes of ~40 s; and (iv) an additional 2 min of effleurage.

The leg to be massaged was randomly selected, and no one except the massage therapist knew which leg had been massaged until after the results were analyzed.

So how to figure out what the massage did? They took three muscle biopsies from each leg: one at rest, one immediately after the massage, and one 2.5 hours after the massage. Then, because they didn’t know exactly what to expect, they did an untargeted whole-genome analysis to figure out which genes reacted differently between the massaged and non-massaged leg. The result:

[W]hen administered to skeletal muscle that has been acutely damaged through exercise, massage therapy appears to be clinically beneficial by reducing inflammation and promoting mitochondrial biogenesis.

How and why does this happen? The researchers suggest that “mechanical stretch or strain during massage treatment” activates the relevant signalling pathways. In fact, they suggest, the mechanism may be essentially the same as conventional anti-inflammatory drugs. Which is very cool. They also checked the rate of glycogen restoring and lactate clearance in the muscles; neither were improved by massage (which, in the case of lactate, we already knew).

So what does this tell us? Massage does something. Do these acute signalling changes translate to a clinically significant difference in muscle recovery a day later? Impossible to say for now. Is effleurage or petrissage more effective than one of those self-massage devices you can buy from late-night informercials, or than a foam roller? Who knows. But it’s a very good start.

THANK YOU FOR VISITING SWEATSCIENCE.COM!

My new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Also check out my new book, THE EXPLORER'S GENE: Why We Seek Big Challenges, New Flavors, and the Blank Spots on the Map, published in March 2025.

- Alex Hutchinson (@sweatscience)

***

One of the big challenges for researchers trying to figure out how to reduce post-workout muscle soreness is that it’s really hard to quantify that soreness. Asking someone “How sore are you?” is important, but highly susceptible to placebo effects; more objective measures like the enzyme creatine kinase (which is supposed to indicate muscle damage) now tend to be viewed as pretty unreliable proxies for muscle soreness. So how about this:

That’s an image from a new study that used an infrared camera to measure skin temperature before and after a series of biceps curls (press release here; freely available article and video in the Journal of Visualized Experiments here). They suggest that skin temperature that remains elevated 24 hours after exercise indicate muscle damage:

This damage in the muscle causes additional heat transfer from the muscle to the overlying skin, which causes a detectable hot spot under the skin.

And sure enough, their study did find elevated skin temperature in the biceps (33.96 C instead of 32.80 C) 24 hours after exercise. The problem is that the temperature returned to normal (32.82 C) after 48 hours. The subjects’ subjective assessment of soreness, on the other hand, was equally elevated after 24 and 48 hours — so clearly skin temperature isn’t a perfect proxy for what we experience as soreness. Still, it could be an interesting way for researchers to look at the early stages of delayed-onset muscle soreness in a quantifiable way. And it makes pretty pictures.

THANK YOU FOR VISITING SWEATSCIENCE.COM!

My new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Also check out my new book, THE EXPLORER'S GENE: Why We Seek Big Challenges, New Flavors, and the Blank Spots on the Map, published in March 2025.

- Alex Hutchinson (@sweatscience)

***

Exercise boosts your immune system — up to a point. A neat new paper in Medicine & Science in Sports & Exercise digs a little deeper into this complicated relationship between exercise and immune function. Specifically, it looks into the response of neutrophils:

When infection occurs, neutrophils rapidly migrate to the infection site (chemotaxis) and ingest the pathogens (phagocytosis).

So how does exercise affect these neutrophils? Well, that depends on what kind of exercise you do. For regular, moderate exercise (“CME,” or “chronic moderate exercise,” consisting of 30 minutes of moderate cycling daily for two months), here are the results:

“DT” is “detraining.” So you can clearly see that regular, moderate exercise boosts the ability of the neutrophils to get to infection sites quickly (chemotaxis) and attack the bad guys (phagocytosis). And in fact, the neutrophils are still ultra-alert for a couple of months after you stop training. In addition, the researchers found that regular exercise extended the life of the neutrophils.

On the other hand, the effects of  “acute severe exercise” (an incremental test to exhaustion) had more mixed results. Chemotaxis was enhanced, but phagocytosis wasn’t, and the lifespan of the neutrophils was shortened — not so good for immune function.

So is this a surprise? Not really — it’s been clear for a long time that exercise has a J-shaped influence on immune function. Some is good, more is better, but beyond a certain point, too much is bad. Run a marathon, you’ll have a slightly elevated risk of catching a cold (or at least suffering from some sort of respiratory symptoms) afterward. But studies like this are needed to understand what exactly is happening in the body, so that eventually we’ll have a better idea of exactly where the curve in the J starts — and possibly figure out some ways to extend the sweet spot of the curve.

THANK YOU FOR VISITING SWEATSCIENCE.COM!

My new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Also check out my new book, THE EXPLORER'S GENE: Why We Seek Big Challenges, New Flavors, and the Blank Spots on the Map, published in March 2025.

- Alex Hutchinson (@sweatscience)

***

The good news: Sidney Crosby is back from the concussions that kept him on the bench for more than 10 months, and he had two goals and two assists in his return against the Islanders last night. But one downside, a reader pointed out to me in an e-mail, is that Crosby’s return may give added credibility to “chiropractic neurology,” the alternative therapeutic approach that Crosby turned to during his rehab. What exactly is this? I don’t know — and I’m not alone:

It’s a field that’s unfamiliar to many traditional doctors, including Randall Benson, a neurologist at Wayne State in Detroit who has studied several ex-NFL players. Says Benson, “It’s very difficult to evaluate what kind of training, expertise or knowledge a chiropractic neurologist has since I have never heard of [the discipline].”

That’s a quote from David Epstein and Michael Farber’s excellent look at Crosby’s rehab from Sports Illustrated in October. A couple of other interesting quotes:

In 1998, at Parker University, a Dallas chiropractic college, Carrick [the chiropractic neurologist who Crosby worked with] worked on Lucinda Harman before 300 students. Two car accidents and a neurotoxic bite from a brown widow spider had left Harman, herself a Ph.D. in experimental psychology, wheelchair-bound and with headaches, during which she saw spots.”[Carrick] asked if they were red and yellow,” she says. “I said, ‘No, they’re green, blue and purple.’ ” Carrick informed the audience that this meant her brain was being drastically deprived of oxygen and that, without treatment, she had six months to live. Harman, now 59, says simply, “Miracle.” But Randall Benson says that “there’s nothing out in peer-reviewed literature supporting” an association between the color of spots a patient sees during a headache and the severity of the oxygen deprivation in the brain.

[…]

Carrick, who has had a handful of studies that have appeared in scientific journals, has never published data on vestibular concussions. “We don’t have enough time to publish studies,” he says, “but we’re doing a large one at Life [University] right now.”

It’s a great piece — fair but rigorous. In some ways, though, the most important quote may be the kicker:

“I don’t think this is a case of trying to do something wacky,” Crosby says. “When someone came along and invented the airplane, people must have thought they were out of their mind. Who thinks he can fly? I’m sure people thought that person might have been stretching it a bit… . At the end of the day, as long as the person getting the care is comfortable, I think that’s what’s important.“

Much as my evidence-based personality protests, I do think there’s some truth to that. Especially in cases like this, where — as with so many health conditions — there isn’t a well-established “standard-of-care” treatment. It’s totally different from, say, Steve Jobs choosing “alternative” forms of cancer treatment instead of surgery. In that case, the potential benefits of the surgery are well-known and well-understood. But many people face health conditions where the verdict of the Cochrane review is basically “there is insufficient evidence to conclude that ANY interventions do any good.” In that case, it’s hard to argue against trying other, unproven approaches rather than simply doing nothing.

Of course, sports medicine is a little different — it’s not life-or-death. For pro athletes, the incentive to try anything and everything in order to return to play (and earn money during their brief career window) is enormous. If I were Tiger Woods or Terrell Owens, I would have tried platelet-rich plasma to speed tendon healing too, despite the lack of evidence that it actually works. The problem is that the use of these therapies by sports stars gives the general public the impression that they’re proven, established treatments — hence the huge surge in PRP over the last few years. Will the same thing happen with chiropractic neurology? I hope not. But on the other hand, if someone who’s been in two car accidents and been bitten by a neurotoxic spider is in pain and hasn’t been able to get relief from conventional treatment, I’d have a hard time criticizing them if they decided to give it a try.