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Is Icing an Injury Really Bad for You? What the Science Says

Today’s article is an excellent review of the effects of cryotherapy, or ice, from my good friend Phil Page, PhD, PT, ATC, CSCS, FACSM.  Man, icing an injury sure has taken some heat (see what I did there…) lately on the internet.  There is a HUGE anti-ice movement.  I’m always amazed at how polarizing social media can be, with people screaming their black or white opinion, when in reality much of what we do is in the grey.  I get questions all the time about wether or not icing is good or bad for you, with many people quick to jump to the conclusion that we should not be icing.  Well, let’s find out what the research actually says.  Phil’s the Director of Research & Education with Performance Health, and one of the best at analyzing the research.

 

Is Icing an Injury Really Bad for You?

You’ve probably heard the debate on whether icing is helpful or harmful. You might be strongly on one side or the other, or maybe you aren’t sure which side you’re on because you’ve heard so many different things.

Despite what you might hear from anti-ice gurus that tend to be sensationalized on the Internet, let’s look at the facts and how we got here.

Ice isn’t the bad guy. Yes, we tend to apply ice in some situations that probably doesn’t help and claim we do so for the wrong reasons.  But the bottom line is that there are several benefits to ice, and ice has not been proven to impede the healing process as many claim.

About 30 years ago as a student athletic trainer at LSU, we frequently used ice, following the research of Dr. Ken Knight, who literally wrote the book on cryotherapy. I, as most other athletic trainers, was keenly aware of the mechanism of ice after an acute injury. As a graduate assistant athletic trainer for baseball at Mississippi State, I continued to advocate ice for my pitchers after they threw. Ice was my best friend.

Suddenly, stories came out that icing was bad for pitchers. As a matter of fact, one story back then was that it actually caused bursitis! Knowing a little about pathophysiology, I quickly dismissed that hogwash…  but the gears were in motion against using ice after pitching.

Fast forward to a few years ago. All of a sudden, ice is again demonized, but this time, it’s a vicious attack:

“Icing is wrong.”

“Ice impedes healing.”

“Icing is harmful.”

Say it ain’t so! Wha are we supposed to do?  Those are some bold claims!

The argument against ice tends to center around ice impeding the healing process as an ‘anti-inflammatory.’ Throughout the healing process (injury, inflammation, repair, remodeling), we need each of those stages to occur in order.  As an anti-inflammatory, the question was if ice actually creates an environment that does not allow the tissue to repair itself?  Interestingly, this same argument came out around the same time as people started questioning NSAIDS for the same reason!

Well, one study did get published (Tseng et al. 2013) titled, “Topical Cooling (Icing) Delays Recovery from Eccentric Exercise-Induced Muscle Damage.” The authors found increased signs of muscle damage after applying ice following eccentric exercise compared to a ‘sham’ application (although I’m not sure how you actually can apply ‘sham’ ice).

Bingo. Proof that ice impedes healing!  Right?  Hold on cowboy. That’s not the whole story.

What you didn’t hear about unless you actually read the study was that the authors concluded:

This study does not provide evidence on whether recovery from pitching-induced muscle damage would be slowed down by topical cooling.”

And while the authors found increased biomarkers in the group receiving cold therapy, there was no difference in strength or pain between the groups.  And I won’t even get into the question of adequate power with an n of 11.  You could argue that the study did not have enough subjects to have much clinical relevance.

Yet, ice was under attack again.

In addition, a few review studies of ice after ankle injuries raised more doubt on the practice of “RICE” (Rest, Ice, Compression, Elevation). The conclusion was that the quality of the research was generally poor quality, and the outcomes were inconclusive.

Note the word, “inconclusive” is not the same as “ineffective.”

And many times, effectiveness of icing was measured by the amount of swelling, rather than the actual healing process and return to activity. And while we know that ice doesn’t do much for swelling after the first 48 hours (Cote et al. 1988), modest cooling has been shown to reduce edema in animal studies (Collins 2008, Deal et al. 2002).

Yet, there we were, left to question if icing for recovery or after acute injuries was actually helping or hurting our athletes.  How did we get to this point?

 

The Claims Against Ice are Largely Based on Pseudoscience

The claim that ice is harmful by delaying the healing process is not supported by science. You may have seen bits and pieces of “science” in the false claim, but it’s a play on science that doesn’t give you the full picture or ability to make such a bold statement.  It’s called pseudoscience….statements that appear to be based on the scientific method, but are not.

Icing is not harmful or wrong to use.

You have witnessed a sham. Like the cup-and-ball game. It happens so fast and seems logical, but it’s a mind-trick.  Here are several things to consider.

Confirmation Bias

This is the tendency for us to accept evidence to confirm our own beliefs or theories. If you think ice is bad, you will tend to accept the information that supports your belief.  This makes us feel good because it confirms our prejudice.

False Logic

If inflammation (A) is necessary to get to healing (C), and ice (B) reduces inflammation (A), then ice (B) must reduce healing (C). FALSE. There is no direct evidence that icing reduces the healing process. In contrast, research supports the fact that ice does not impede healing (Vieira Ramos et al. 2016).  Granted, this was a study from an animal model, but who wants to be a human subject to test that theory?

Circumstantial Evidence

Evidence that attempts to prove a fact by connecting a related event or condition to a conclusion, as opposed to direct observation, is considered ‘circumstantial.’ This could be one of the most common ways science is used to incorrectly support claims. The presence of biomarkers in the blood may be an indirect measure of muscle damage, but it does not prove ‘cause-and-effect’. (Remember the DOMS study I referenced above?) Guilt by association is not the same as ‘causation.’ Using surrogate measures to make a definitive conclusion is a slippery slope.

Inconclusive Conclusions

Poor research (or no research) cannot serve as a basis for a conclusion on efficacy, let alone harm. The evidence on applying ice after an acute ankle injury is ‘inconclusive’ based on only a few studies of poor quality (Bleakley et al. 2004; van den Bekerom et al. 2012). There are no studies that applying ice after an ankle injury reduces recovery time (Hubbard et al. 2004). In fact, one study showed that early application of ice (< 36 hours) resulted in significantly faster return to play compared to delayed cryotherapy (Hocutt et al. 1982).

Comparing Apples to Oranges

Equating 2 things that appear similar, but are actually different, is not a fair comparison. Comparing DOMS to the healing process is not an accurate comparison. We know more about soft tissue healing after an injury than we do about the mechanism of DOMS, which is not a true model of an acute injury. Don’t forget, inflammation is not the same thing as swelling and edema!

Selective Science

Unbalanced reporting. Cherry-picking the literature. All signs of pseudoscience. The anti-ice movement has neglected years of research on the mechanism of ice after injury, focusing only on a select few studies that support (but in reality DON’T support) their argument. Dr. Knight explained that ice is not an ‘anti-inflammatory’ per-say (Knight, 1976); rather, it prevents the secondary injury to tissues by dampening the negative physiological effects of widespread inflammation. His position has been supported by other researchers as well (Ho et al. 1994, Merrick et al. 1999). And to top it off, one study quoted against icing (Bleakley et al. 2004) even concluded, “The sooner after injury cryotherapy is initiated, the more beneficial this reduction in metabolism will be.” Hmmm…the anti-ice crowd must have missed that statement.

 

The Benefits of Ice

Ice is not wrong or harmful.  The theory that ice impedes the normal healing response by limiting inflammation is not well documented in the literature. If you have been swayed by this on the internet, I would urge you to try to research this more and scrutinize the literature.  Be careful of what you see on the internet and ALWAYS seek to validate anything yourself.

Ice has plenty of benefits and clinical validation.

Proper application of cryotherapy can reduce secondary injury and reduce edema formation if applied within the first 36 to 48 hours (remember, ice doesn’t reduce swelling after the acute injury phase, and may not play a huge role in inflammation or recovery).  We do know that ice helps reduce pain, spasm, and guarding, allowing more mobility (Barber et al. 1998, Raynor et al. 2005).   More than anything, ice is a convenient and potent pain reliever, so it’s ok to apply ice to ‘chronic’ conditions as a safer pain reliever at any time. In fact, cryotherapy has been shown to decrease the amount of prescription pain medications needed after surgery (Barber et al. 1998, Raynor et al. 2005).

Sure, there are some times that ice is overused or erroneously used fort the wrong reasons, like reducing swelling after 48 hours.  The clinical research may not be conclusive, but there is no direct evidence that ice impedes healing. The argument that ice is ineffective or harmful is based on pseudoscience, and we need to be aware of this tactic.

Just be careful what you read, everyone has a bias.  #StandUp4Ice.