Uncovering the Data on Recovering

To be successful as a runner requires proper training.  That definitely means the right volume, intensity, and density of running.  However, it also entails doing the right things in between runs to allow an athlete's body to adapt and repair so that it will be ready for the next race or workout and hopefully stronger when that time comes. 

Running takes a toll on the body, and so optimizing recovery plays a vital role.  The running scene--be that Runner's World, Instagram, or the local store--is saturated with products and practices that promise to promote recovery.  Some have lines of people--world class athletes, weekend warriors, and well-meaning high school coaches and teammates--willing to swear by them. 

But which ones actually work as advertised?  My intention in this article is to share the recent evidence and help in forming a verdict.  Most of the info is courtesy of the book Good to Go by science journalist Christie Aschwanden, which I've been reading over the off-season.  According to Aschwanden, it's not as simple as this recovery method works and that one doesn't.  They're all on a dual spectrum of how much evidence we have for a recovery modality and how much effect that evidence suggests.  I think some of the results might surprise you.  They certainly did me, as many of the things I've used and prescribed don't actually seem to have much impact.  

Christie Aschwanden won a state title in the 1600m in high school and ran cross country at the University of Boulder before a knee injury led her to cycling, where she was part of the 1993 national championship team. She graduated with a degree in biology. The former lead science writer at FiveThirtyEight, she now produces and hosts UNCERTAIN, a podcast about scientific uncertainty.

The Placebo Pitfall

The biggest consideration when evaluating recovery modalities is the placebo effect, which as many know is the phenomenon where an individual experiences improvement from a treatment that has no known therapeutic value.  It's one of the mysteries of the psychosomatic interactions between the mind and body.  The medical community has extensively documented the placebo effect, but it shows up in the athletic recovery world as well.

Put simply, if a runner believes a recovery protocol will improve their condition, that belief alone can trigger changes in the body that do actually make the situation better without any contribution from the treatment itself.  In theory, chewing bubble gum could make a runner feel like their soreness and pain had decreased if they had a vested belief that bubble gum was a recovery miracle.  In that sense, the answer to the question "Will this help my recovery?" is "Probably, if you think it will."  

The concept gets even more interesting when additional layers are added.  One of these is an active placebo.  When a treatment causes some sort of sensation--like a tingling or a burning feeling or a taste in the case of something ingested--it tends to generate an even larger placebo effect than one where an individual feels nothing.  Another is the agency component.  If people get to choose from among treatments rather than being assigned to them, the treatment tends to show a greater effect.  And none of this has anything to do with the actual treatment itself.  

The medical community has ways to help isolate the effect of a treatment from the placebo effect, the most common of which is a double-blinded placebo-controlled study.  In these cases, test subjects are separated into two groups, one of which receives the actual treatment while the other receives a placebo, generally something like a sugar pill or saline solution meant to mimic the real treatment.  This makes it possible for the study to be conducted without either the researchers nor participants knowing which group is which.  Any effects observed in the placebo group can be deducted from the effects in the treatment group, with the remaining effect understood as coming from the treatment.

This is a simple enough approach with oral medications or injections, but many recovery modalities don't lend themselves very well to placebos.  How do you convince someone they are getting an ice bath without giving them an ice bath, let alone convincing the researchers?  The same applies to things like massage, meditation, and a host of other recovery modalities. 

​In the end, that makes it very difficult for researchers to know whether an $80 pair of compression tights improves recovery or whether it's from a belief that could possibly have come just as easily from something like a free hot shower.  That being said, let's take a look at some of the more common recovery approaches.

Quiet Time

Let's start with the recovery technique that studies suggest has as much impact as almost all of the others combined.  It's called rest.  The most powerful version is sleep, and study after study has linked decreased sleep with impaired recovery and lower performance.  For a typical high school athlete, that means anything below nine hours of sleep.  If someone is only getting 6 or 7 hours of sleep, an extra half hour of shut eye is going to do more than thirty minutes of foam rolling or icing ever could.  Quality of sleep also makes a difference.  The importance of sleep really can't be overstated, which is why I plan to do an entire post on it down the road.

Besides sleep, rest can also simply mean quiet time where we break from all the hustle and bustle.  Stress is stress, and so any opportunity for time that doesn't add to that bucket is a win.  Studies do support enhanced recovery from such practices.  Some people push that to the extreme with things like float tanks, but as a Catholic I've found that quiet time in prayer--besides the primary intent of spending time with the Lord--can have this same effect.  Aschwanden suggests that aside from the placebo effect, this might be the real benefit of many recovery protocols.  While someone is sitting in an ice bath or wearing compression boots, they aren't doing anything that is going to add stress, which is going to promote recovery regardless of whether the practices actually make an active difference.

Despite their popularity with athletes like Stephen Curry, it's probably the stillness that contributes to recovery more than the float tank and the $50-100 it will cost you per session.

Refueling

Besides rest, nutrition is the second best recovery practice, backed once again by ample research.  For runners, the primary needs after training are protein and carbohydrate.  The body uses protein for repair and growth in the muscles.  Carbohydrates replenish glycogen stores.  Numerous studies show improved recovery given adequate intake of these macro-nutrients.  

Many insist on an optimal ratio of carbs to protein in recovery of four to one.  There's some evidence to support this, but simply getting enough of both seems to have a far greater impact than the precise ratio.  

Some insist that an optimal window of somewhere between 30-60 minutes after exercise when refueling is most critical and/or effective.  There's actually very little evidence to support this.  It seems like as long as the body refuels at some point after exercise, the body will be able to recover.  

Finally, the body has no way of differentiating the source of these macro-nutrients.  While other ingredients and additives might be of concern to general health, the body recovers just as well given fast foods as foods peddled by the recovery industry so long as the macro quantities are identical.  This was supported by  a study in which cyclists were split into two groups, one given McDonald's after their workouts and the other an assortment of Clif, Gatorade, and PowerBar products.  Their glycogen stores were tested and they were subjected to a time trial.  There was no significant difference between the two groups.  

Our post-race chocolate milk routine did get a plug in the book. It has the same macro counts and performance effect as more expensive recovery supplements like Endurox R4, which costs nearly $3 a serving.

Ice

Now we've hit the murky waters, perhaps in frozen form.  Icing--whether the bags and plastic wrap I spent plenty of time with in high school, more immersive versions like a bath in the $1200 Ice Barrel 300, or even cryotherapy--has long been a standard recovery practice, perhaps the most popular of them all.  

However, despite its near ubiquitous presence, very little evidence actually shows a recovery benefit to icing.  Does it reduce swelling and inflammation?  Yes.  Does it numb pain?  Absolutely.  Does it make the damage causing the pain and swelling heal any faster?  Not really.  In fact, the first two effects might actually be obstacles for the third.

Swelling is generally the result of increased blood flow to tissue.  This blood contains oxygen and nutrients that aid the healing process.  Aschwanden uses the analogy of emergency vehicles responding to an accident on the interstate.  This is going to create congestion on the road, but ultimately it will also bring help to the victims.

The problem with ice is that it reduces swelling by cutting off blood flow.  In the analogy it would be like government officials closing the road completely.  Emergency vehicles wouldn't be able to get in or out of the accident scene.  By cutting off blood flow, icing can actually prevent the very things the tissue needs from ever reaching it.  In the case of minor damage typical of a workout, this would limit the body's adaptation process to become stronger.  In cases of injury, it can prolong the state of damage.  

The second issue is that the decreased pain felt after icing can give an athlete the illusion of recovery.  This can lead them to push their body before it is ready.  Once again, in the case of standard training damage this cuts short the time for supercompensation.  In the case of injury, this can lead an athlete to add additional damage to an injury that really needed more recovery time.  

So if an athlete has multiple games or races in a short span of time, icing might reduce the swelling and pain to the point they could compete.  But it wouldn't improve recovery, and for an athlete looking to heal or strengthen, it might actually be detrimental.  

Icing often plays into what Aschwanden calls the "hurts so good" placebo, where individuals believe in an effect because of the discomfort it causes.

Ibuprofen

Much of what can be said about icing applies to ibuprofen and other nonsteroidal anti-inflammatory drugs (NSAIDs).  Like ice, there is no evidence they decrease delayed-onset muscle soreness, a common indicator of recovery.  A study of participants in the Western States Endurance Run, a 100-mile mountain race in California, showed no difference in post-race muscle soreness between those who took ibuprofen and those who did not.  Ibuprofen works by limiting the production of prostaglandins, a type of lipid produced at the site of tissue damage that work as signals for the body to begin the inflammation process.  

Going back to the previous car accident analogy then, taking NSAIDs would be like shutting down all the cell towers.  No one at the site of the accident can call for help.  That means the city doesn't know about the accident (in other words no pain), but it doesn't mean anything is being done about the accident.  

 Like ice, the pain relief of NSAIDS can lead athletes to overtrain in ways that prevent adaptations and worsen injuries. Add to that the risks of stomach ulcers and in extreme cases even rhabdomyolysis that can stem from ibuprofen overuse, and concerns only increase.  

With increased dosage, the risks of NSAIDs go up, while the chance of improved recovery really doesn't.

Massage

I think at last count I have 6 foam rollers at my house, not to mention an assortment of lacrosse, racket, and golf balls.  There's also the massage gun and the stick.  While I've never received massage treatment from a professional, I've certainly bought into the industry at large.  We used many of these same tools in my high school days, and even as a math teacher I can't count how many times I've loaned a foam roller to an athlete.  People in the sport I trust greatly push deep tissue massage routines.   

But where does the evidence stand?  The problem is there's not a lot of research.  One reason is the increased variability compared to other modalities.  Someone can control how long to ice or how much ibuprofen to take, but otherwise the protocol is pretty straight forward.  With foam rolling, there are questions of when to roll, where to roll, how to roll, how long to roll, what roller to use.  It's hard to account for all of this variability in one study.  A meta analysis on existing research indicates small but statistically significant benefits. There have been studies to show decreased soreness, but they are limited not only in number but in sample size.  For example, one study showing positive effects only involved eight participants, though a study last year with 60 participants did show positive effects as well.  

There are other interesting observed phenomena, such as individuals rolling their right leg and then experiencing decreased soreness in the left leg that they never rolled.  There's also no accepted explanation of why rolling works.  The most common one is that it breaks up adhesions in fascia, the connective tissue that surrounds muscles.  It's important to note the difference here compared to ice and ibuprofen, where there are numerous studies showing no effect.   Here it's more a case of the jury still being out.   Until that changes, given the limited risks of foam rolling, defaulting to expert opinion makes sense.  Right now that's still in favor of using them.

From its founding in 2002 until the brand was sold off in 2014 Trigger Point Performance, a leading producer of self-massage tools, grew to $60 million in annual sales. That number has only increased in the time since it was acquired by global fitness corporation Implus.

Compression

My foam roller collection pales in comparison to my assortment of knee-high running socks.  I mostly wear them because they're goofy and stand out, which maybe means I'm less likely to get hit by a car on a road run.  But for many people, they swear by the ability of compression socks and sleeves and tights to promote recovery.  The extreme end of this belief would be use of pneumatic compression devices like the boots produced by Normatec.  

There's some variability here with products, but the compression boots are pretty straightforward and have been extensively tested.  Clear benefits for individuals like my grandpa with poor circulation have been thoroughly documented, but not as much for generally healthy athletes.  While some small and inconsistent evidence of improvement in biomarkers has been seen, there's been zero evidence of increased recovery by performance measurements.  

While Normatec boots might force you to sit still long enough for your body's own recovery abilities to have a chance to work, the $800 they would cost you could keep you on the couch watching Netflix for much longer.

Stretching

I've talked enough on this blog about the issues with static stretching as a warm-up practice, but many people also insist on post-exercise static stretching to promote recovery.  This would certainly avoid any concerns about stretching limiting workout performance or increasing injury risk, as some studies have shown.  But is there any benefit after a run?

A 2021 meta-analysis showed no significant contributions of post-run stretching to reduced muscle soreness or strength recovery compared to passive recovery.  The researchers acknowledge that the amount of research has been limited.  Like foam rolling, this is complicated by variations in stretching protocols.  Nonetheless, none of the existing studies suggest a significant benefit, and that is at least concerning.

Recovery Monitors

Pretty much every fitness watch today has some sort of recovery score that suggests how much time off you need and whether you are ready for more work.  Obviously wearing such a device isn't going to directly enhance recovery, but it still plays a potentially influential role in the process, as many people place a great deal of trust in the metrics it offers.  If a watch says someone only needs a day off before their next workout, many people will head back out to grind in 24 hours, whether or not that was actually too soon.  In that sense the accuracy of these devices matters greatly for recovery.

The challenge is that all of these devices are different.  The companies also don't exactly publicize their "proprietary" algorithms for calculating scores, so knowing exactly what data they factor in and to what degree is hard to guarantee.  Many of these companies are also regularly updating devices and software, so this is an evolving situation.  That in part explains why few extensive studies exist.  

One involving the Whoop band and elite swimmers showed little correlation between its recovery score and lab measurements of recovery.  Beyond that, simultaneous comparison of these devices raises skepticism.  I've read numerous articles of athletes who have worn devices from two companies at the same time during workouts.  At times they were in general agreement, but on other occasions their recommendations were wildly different on recovery time, meaning at least one of them would be misguiding an athlete.

In the end, Aschwanden has reached the conclusion that the best judge of recovery outside of a lab (and maybe even inside one) is an athlete's own body.  Like running by feel, recovering by feel is a learned art, but a powerful one when mastered.

WHOOP offers incredibly accurate heart rate values and surprisingly reliable sleep metrics, but the $30 per month subscription doesn't seem to offer the most trustworthy recovery scores at this point.