Tag: sports technology

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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)

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Okay, I admit I enjoyed making fun of the “cryosauna” last fall, after it emerged that Alberto Salazar had arranged to have one shipped to New York so that Dathan Ritzenhein could use it before the New York Marathon. With the manufacturer promising “tighter, healthier skin,” “increased libido,” and “stronger, fuller hair,” the concept was ripe for a few jokes — especially since there was no actual science supporting its use for athletes.

But now I have to get serious, because a legit study has been published, funded by the French Ministry of Sports (and not by the manufacturer — actually, it’s a German company that made the cryosaunas used in the study). The full text is freely available via this link. The study had 11 trained runners do a pair of 48-minute hilly treadmill runs (i.e. including enough downhill to trigger muscle damage and soreness) separated by at least three weeks. After one of the runs, they were given three minutes of whole-body cryotherapy at -110 C immediately after, and then again once a day for the next four days. After each cryotherapy session, blood tests were taken to measure a bunch of inflammation and muscle damage markers. After the other run, they followed the same protocol, except replacing the daily bout of cryotherapy with 30 minutes of passive sitting.

One thing to emphasize: this study appears to have been very carefully executed. Throughout the study, the subjects were told exactly how much they were allowed to run, and they weren’t permitted to use anti-inflammatories or other recovery aids. They also controlled food and drink intakes.

The results? They’re pretty complicated because they tested a lot of things. For most of the markers, there was no difference. But there were three key differences:

• C-reactive protein, a marker of muscle damage, stayed almost unchanged in the cryotherapy group, whereas it spiked after 24 hours in the control and was still elevated three days later.
• Interleukin-1beta, a pro-inflammatory cytokine produced after strenuous exercise, was slightly suppressed by cryotherapy (though not by much, if you look at the data below).
• Interleukin-1ra, an anti-inflammatory cytokine inhibitor that counteracts the pro-inflammatory cytokines, was temporarily but significantly enhanced immediately after the post-exercise cryotherapy session.

Here’s what the data for those three factors looked like (WBC is whole-body cryotherapy; PAS is passive recovery):

So does this settle any debate? Well, there’s always a big gap between seeing a minor change in some blood test and translating that to a functional benefit for an athlete. Does cryotherapy permit a better next-day or day-after-tomorrow workout? We don’t really know. On a more general level, do the benefits of (hypothetically) more rapid recovery outweigh the (hypothetical) disadvantages of suppressing the inflammatory signals that tell your body to adapt and get stronger? Again, we don’t really know — that’s still in the realm of coaching art, not science. Is a massively expensive cryosauna any better than a bathtub with a few blocks of ice thrown in? Still don’t know.

But having said all that, this study does suggest that we can move the cryosauna from the category of “wacky techno-schemes that sound like you mail-order them from the back of a comic book” to “serious recovery modalities that are as likely as anything else we currently rely on to work.” (Though I’m still reserving my judgement on the “better hair” claims.)

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)

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Platelet-rich plasma therapy was a super-hot topic a couple of years ago (see earlier blog posts about it), in part because of reports that top athletes like Tiger Woods were using it to speed their recovery from injuries. These days, the fuss has died down a bit. The novelty is gone, subsequent studies haven’t produced the “miracle” results promised by initial case reports, and maybe no one wants to emulate Tiger Woods anymore.

Anyway, studies of PRP continue to trickle in, but the picture isn’t necessarily getting much clearer. Two new studies have just been posted online at the American Journal of Sports Medicine, one of which is a randomized trial of PRP for tennis elbow by researchers in Greece. The design seems pretty good in theory: 28 patients were split into two groups; one group received an injection of PRP (their own blood, spun to produce plasma with elevated levels of healing-enhancing platelets), while the other group received an identical injection of their own unenriched blood. This should eliminate the problem of placebo effects (which are very big in invasive procedures that involve lots of needles), and test only whether the platelets themselves make any difference.

But there’s a problem:

This is a single-blind study. Patients were aware of the treatment because it was practically difficult to mask the process.

I don’t understand this. Maybe there’s something I’m missing — if you know why it would be “practically difficult” to mask the process, please let me know. It seems to me that all you have to do is put the blood-spinning machine in the room next door, and you’re in business with a double-blind study. But that’s not what they did — and to me, that’s an enormous problem, given how much publicity PRP has received over the past few years.

Anyway, the results: they measured subjective pain and perceived elbow function at various points over the next six months. There was only one case where the two groups showed statistically significant differences: pain was lower in the PRP group after six weeks, though the difference was no longer significant at the next measurement (3 months). On the other hand, if you ignore “statistical significance,” the trend was that the PRP patients did better in every measurement.

So how do you interpret these results? It’s pretty clear that the authors of the paper are big boosters of the technique:

[T]here is enough proof to support the superiority of PRP treatment over autologous blood, regarding pain, in the short term…

More studies on this topic could further enlighten aspects of this promising treatment…

In conclusion, we showed that PRP led to pain relief earlier than autologous whole blood, and we believe its application will be increasingly widened in the near future…

Really, I don’t think they showed any such thing. They found results that were statistically insignificant in five of their six outcomes, using two measurements that are largely subjective, in an experimental design that does nothing to eliminate placebo effect for one of the most heavily hyped sports medicine treatments of the past decade. To justify the cost and extra effort required for PRP therapy, they’re going to need more definitive results than that.

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)

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Yet another salvo in the ongoing debate about whether platelet-rich plasma (PRP) therapy — sometimes known as “blood spinning” — is a miracle tendon healer or an expensive placebo. At an American Orthopaedic Society for Sports Medicine conference in San Diego, researchers presented the results of a new study of PRP for rotator cuff tendon repair — and the results weren’t encouraging.

The study involved 79 patients who all received standard surgical rotator cuff repair and post-operation rehab; half of them were randomized to receive a form of PRP treatment. There were “no real differences” between the groups:

“In fact, this preliminary analysis suggests that the PRFM [the form of PRP used in the study], as used in this study, may have a negative effect on healing. However, this data should be viewed as preliminary, and further study is required” said study author Scott Rodeo, MD, of New York City’s Hospital for Special Surgery.

Right now it’s just a conference presentation; the study will presumably be published eventually, at which point we’ll get some more details on the design and specific results of the study. But the scientists still seem optimistic:

Researchers think there may be several reasons for a lack of response in healing, including variability in the way platelets are recovered, platelet activation and the mechanisms for the way the PRFM reacts with the tendon cells. The study was also unable to document the number of platelets actually delivered to patients who received the PRFM…

“Additional research needs to be performed to figure out the mechanisms for why PRP is successful in healing certain areas of the body and not others…” said Rodeo.

I’m not really sure which areas of the body he’s talking about. I only know of one properly controlled clinical trial that came to a positive conclusion, on tennis elbow — but even that study was subject to criticism. So far PRP is one of those ideas that makes perfect sense in theory, but hasn’t yet proven itself in practice.