Cold is really catching these days. Aubrey Marcus, whom I recently filmed a nice podcast with, was asked about his winning daily behaviors on another show. The very first thing he mentioned was “exposure to cold.” His practice is finishing his morning shower with a three-minute stint at full cold setting. He mentioned the hormonal benefits but also the mental edge he gets from psyching up and accepting the challenge instead of wimping out. He also cited research that people who engage in therapeutic cold exposure catch fewer upper respiratory infections. Hence, like many other elements of conventional wisdom, the old wives tale is backwards. Of course, we are talking about acute and optimal duration cold exposure, not prolonged exposure to elements that weaken your resistance and contribute to immune disturbances.
As with keto, there’s much more to be learned in this burgeoning field before we can operate in definitive (hence today’s title). Today, however, I’ll expose you (the first of more double entendrés to be on the lookout for) to important concepts and best practices so that you may enjoy the vaunted benefits and avoid some of the negative effects of going about cold exposure wrong.
Cold therapy has been around forever as in the athletic world—a central element of injury treatment and post-workout recovery. Ice packs wrapped on aching joints are a staple of every high school, college and professional team locker room. The iconic stainless steel cold whirlpool has been a post-workout destination of professional ballers for decades, and Olympic distance runners have inspired millions of recreational runners to dutifully wade into a cold stream, lake or pool after long runs to soothe and revitalize inflamed muscles. In recent years, whole body cryotherapy clinics have exploded in popularity, making grand promises in return for $45-$90 (the latter in NYC) for a three-minute session in a chamber blowing air at 190-255 degrees below zero Fahrenheit. I haven’t tried cryo, but let’s just say I’ve heard it stings.
In writing Primal Endurance, my co-author Brad Kearns and I studied the cold therapy subject extensively to convey some best practices in the recovery chapter of the book. For this article, we also consulted with Dr. Kelly “K-Starr” Starrett—thought leader on all things mobility, rehab, prevention, and performance (check MobilityWOD.com or Becoming A Supple Leopard for cutting edge strategies that will keep you moving optimally and avoiding breakdown and injury) and reviewed numerous articles, which you will find linked or at the end of the post.
It appears that while cold therapy can offer some proven benefits for inflammation control, enhanced cellular, immune, and cognitive function, and recovery from exercise, numerous elements of cold therapy claims seem to be hype, notably the expensive cryochambers (cold water is better) and the potential of cold exposure to reduce body fat (cut grains and sugars instead!) Worse, the prominent cold therapy practice of post-exercise immersion into cold water or application of ice appears to be counterproductive, compromising potential fitness gains generated by hard workouts.
What NOT To Do…
The most emphatic suggestion made by K-Starr is that cold exposure should happen far away from the stimulus of workouts. While it feels soothing to wade into the icy river right after a run or to relax with an ice pack on your back after a pickup basketball game or CrossFit session, blunting post-exercise inflammation can compromise the adaptive response to workouts, of which inflammation is a critical component. Your muscles becoming inflamed during exercise—and remaining that way for hours afterward are part of how they become stronger and more resilient for future performances. In the hours after workouts, your muscles and other body systems are challenged to naturally repair exercise-induced damage, recalibrate to homeostasis, and replenish depleted cellular energy. Cold exposure also inhibits the function of the lymphatic system in clearing inflammatory toxins from the bloodstream. The takeaway: while cold feels great after workouts, don’t do it.
Furthering this concept about letting inflammation run its course, I know world ranked pro triathletes are experimenting with a complete avoidance of not just cold therapy, but also stretching, massage, and myofascial release (foam rolling.) The thinking here is that when those lower back muscles stiffen after 80 miles of hilly cycling, or hamstrings tighten up after a set of 800s on the track, loosening them up with massage strokes or foam rolling will weaken them and counteract the training stimulus. Again, these unwinding therapies might feel great, but you are teaching the central nervous system to relax the muscles that you just asked to contract with great force and duration for the workout. Andrew MacNaughton, former elite pro triathlete and current coach of both top professionals and recreational endurance athletes, says succinctly: “Don’t help your body, otherwise you lose some of the adaptation you’re seeking through your challenging workouts.”
The stuff is so counterintuitive that it becomes intuitive. Are you with me? Consider how it’s now widely understood that static stretching weakens muscles for up to 30 minutes and that you should not static stretch before workouts. This seems like a related principle applied to post workout. Keep in mind that we are isolating this “leave it be” concept to the topic of fitness adaptation. If you are trying to recover from (or prevent) injuries, massage, stretching, and foam rolling can make a valuable contribution—even in and around workouts as directed by an expert. Good old ice is still a recommended treatment in the immediate aftermath of an acute injury to help contain the swelling to the injured ankle (e.g., pickup basketball game) or eye (e.g., parking lot fight after pickup basketball game.)
However, the now dated RICE (Rest, Ice, Compression, Elevation) protocol for injury healing after the ~24-hour acute phase has been replaced by ECM (Elevate, Compress, and Move). Starrett is a leading advocate for ECM, with the emphasis on Move as the top priority for those sprained ankles or stiff calves. Look at some of K-Starr’s stuff on YouTube (like the amazing Voodoo Floss treatment), or read Becoming a Supple Leopard, and you’ll realize that many of today’s soothing therapies and gadgets can be bested by flexibility/mobility drills to help you move with more efficiency and less injury risk in the first place.
Back to cold therapy—it appears the greatest benefits accrue to the central nervous system, cardiovascular system, and immune system rather than the muscles. It’s difficult if not impossible for cold exposure to speed the healing of muscle damage incurred during training. Patience and increased general everyday movement are the big ticket items here.
In recent years, I’ve made a concerted effort to take frequent short walks or perform very light calisthenics or mobility sequences in the hours after a high intensity sprint workout or Ultimate Frisbee match, and it really seems to help me wake up the following day with less stiffness. My Primal Collagen Fuel regimen deserves tons of credit here too; it’s been an absolute game changer, particularly as I continue to insist on doing explosive jumps, burst and lateral movement against fit 20- and 30-somethings on the Ultimate field (yes, I’ve discovered that there are some big time gamers in Miami too!)
I was suspicious of the cryotherapy craze from the start, and Starrett concurs. Research is building that cryotherapy doesn’t deliver the same level of benefit that water exposure does. Starrett even observes that folks following a devoted cryo regimen don’t seem to tolerate cold water very well! Instead, for the price of only a handful of cryo sessions, I suggest you instead go to the cutting edge of cold therapy with an inexpensive and easily-accessible chest freezer regimen—details shortly.
When Is The Best Time For Cold Therapy?
Allow for a minimum of a couple hours, preferably more, after workouts before introducing cold exposure. Perhaps the best time for cold exposure is first thing in the morning for a cellular and central nervous system energizer, and also right before bed in order to help lower body temperature—a key element of transitioning into a good night’s sleep.
Chest Freezers: Not Just For Grass-Fed Beef Anymore
If you’re in Finland or in the Colorado rockies and have a year-round cold lake or river nearby (shout out to body hacking guru Ben Greenfield, author of Beyond Trainingand host of Ben Greenfield Podcast, who indeed has a cold river running through his property outside Spokane, WA), hey—you’re good to go! For the rest of us who don’t have a readily available natural source of cold water that’s reliably under 60 degrees (a good upper limit to observe for therapeutic practices, down to a lower limit of just above freezing), it’s time to talk about the wonder world of the chest freezer. Yep, the same item previously recommended on MDA for storing big orders of Internet-sourced grass-fed beef and other bulk-order treasures.
The idea here is to repurpose a chest freezer into a readily available, any time, any place cold plunge (even Miami, although I don’t think my high rise would allow me to sneak one into the first floor fitness center.). My Primal Endurance and Keto Reset Diet co-author Brad Kearns has plunged deep into the cold therapy scene (that’s #3 double-e if you’re keeping score) with a deluxe chest freezer setup and twice-a-day regimen of brief immersion into near-freezing water.
What you do here is take a 12-15 cubic foot, top opening chest freezer, fill it with water, and then run the motor on a timer for only around 1.5-4 hours per day—depending on the power of your unit, your ambient temperatures, and your desired exposure temperature. For a moderate investment of perhaps $200 on Craigslist or $400 for an ample-sized new unit (Brad grabbed this one with free home delivery), you are in the cold therapy business.
Brad’s preferred water temperature is 33 ºF (icicle alert!), maintained through continual tweaking of the 24-hour timer. Other enthusiasts like to keep water anywhere from 45-60 degrees, with exposure times ranging from 4 minutes at 44 degrees (easy to remember, per Dave Kobrine in Newport Coast, CA—Brad’s initial inspiration for cold therapy) to nearly 10 minutes at 60 degrees. Starrett, who keeps his water in the forties and has twice-weekly gatherings of friends for what he calls “church services” consisting of contrast therapy between chest freezer and hot sauna, confirms that there are no strict protocols to tout as superior to others, and surely significant individual variation in cold tolerance. “Get out before you start shivering!,” Starrett exclaims. “Never stay in to the extent that you suffer or experience pain or burning. Gabby and Laird suggest that if you’re in there long enough to shiver, you’re just showing off.”
Brad describes how he used to set a timer for three minutes at 33 ºF and tried to last that long but then realized that this could compromise the intended purpose of enjoying a Zenlike, mood-elevating start to the day. Instead, he prefers to start with a full submerging, then move hands and head out of water to complete a cycle of 20 slow, deep, diaphragmatic breaths while otherwise fully immersed—which ends up taking around three minutes. As cold water master Wim Hof has popularized lately, pairing a breathing regimen with your cold water immersion will enhance the circulation and oxygen delivery benefits.
Check out Brad’s video (completed in only one take), in which he describes (coherently, while sitting in freezing water) the benefits and setup logistics—everything you need to get started:
Benefits of Cold Exposure
The shock of cold exposure stimulates assorted fight or flight hormonal processes, which deliver an adaptive benefit because the stressor is brief. Contrast the prolonged fight or flight stimulation of hectic modern life (or exposing yourself to cold for too long and catching a cold—duh), which leads to breakdown and burnout.
Optimally brief cold exposure is a hormetic stressor—a natural stressor that delivers a net positive effect. Your heart rate and respiration increase as a way to try and keep warm, increasing blood flow and oxygen delivery throughout the body. Norepinephrine floods your brain, boosting vigilance, focus, attention and mood, and reducing pain and inflammation. The norepinephrine spike from cold exposure delivers what we often call an endorphin rush—natural pain relief and an enhanced sense of well-being.
Dr. Rhonda Patrick, one of the absolute best communicators of cutting edge health and longevity science anywhere, cites research that norepinephrine can rise 200-300 percent with just a 20-second immersion into freezing water a couple times a week (imagine going three minutes, twice a day like Brad—no wonder he was such a big help with this article). Patrick explains that norepinephrine also helps reduce inflammation by inhibiting inflammatory cytokines like the noted bad guy TNF-alpha, a known accomplice in many modern disease patterns.
Quelling inflammatory cytokines is also believed to help battle anxiety and depression. A researcher named Nikolai Shevchuk was quoted in a Fast Company article by Chris Gayomali, speculating about the mechanisms by which cold exposure can boost mood: “probably the stimulation of the dopaminergic transmission in the mesocorticolimbic and nigrostriatal pathway. These dopaminergic pathways are known to be involved in the regulation of emotions. There is a lot of research linking these brain areas to depression.” Indeed, it’s been chronicled that VanGogh was treated in an asylum for depression with two-hour cold baths, twice a week, to combat his well-known condition of depression.
Further tidbits were offered in the Fast Company article from Australian cold water researcher Ned Brophy-Williams on the anti-inflammatory benefits of cold water immersion: “It moves blood from the peripheral to deep blood vessels, thereby limiting inflammation and swelling and improving venous return. Metabolites and waste products built up during exercise can be efficiently removed by the body and nutrients quickly replenished to fatigued muscles.”
Carrying on if you’re still not convinced… Your lymphatic system is activated by cold exposure, helping speed the clearance of toxins from tissues throughout the body. You also elicit an enhanced anti-oxidative defense with increased T cell activity to improve your immune function.
Finally, you may have heard Dr. Patrick promoting the hot topic of heat shock proteins, and how sauna/heat exposure can deliver assorted health benefits. Patrick also informs us that cold exposure releases so-called cold shock proteins such as RNA binding motif 3 (RBM3) that are linked to the regeneration of synapses in the same manner as heat shock proteins. As the Finns have known for centuries, it seems like temperature alterations—deliberate exposure to both cold and hot—deliver phenomenal health benefits.
Cold Exposure—The Right Way—To Boost Recovery
For fitness enthusiasts looking to speed recovery with cold therapy, it’s now clear that the immediate post-exercise inflammation reduction is potentially harmful, and that implementing a simple daily regimen of morning and/or evening exposure can deliver the aforementioned benefits without compromising fitness adaptations. In recent years during the winter months in Malibu, Carrie and I would end our evenings with some 104F spa time, interspersed by quick visits to the sub-60F pool and back to the spa. I’d always end with a few minutes in the pool, leaving me wonderfully relaxed, cool, and ready for sleep. Brad’s morning chest freezer ritual looks as good or better than a morning caffeine blast to get going on a busy, productive day.
Beyond the exciting emerging science, anecdotal evidence from enthusiasts also suggests that toughing out a cold shower or committing to a focused cold therapy regimen has profound mood elevating effects. Primal Blueprint’s own Brian McAndrew (yeah, check out what our guy behind the camera looks like!), who produces our podcasts and fabulous videos on both our YouTube Channel and our comprehensive online multimedia educational courses, has dabbled in cold exposure, using contrast therapy at his health club (going back and forth between the ~50F cold plunge and the sauna at his Portland, OR health club), or just lingering up to his torso in a wintertime cold swimming pool. Brian relates, “All I know is that the worse I made myself feel in the moment [by staying longer in the cold], the better I felt afterwards in regards to mood. This was true for both cold and hot. Having the cold plunge and sauna together lets you go to further extremes, because you know you can get immediate relief at any moment with contrasting cold or warmth.”
Cold Exposure Gives Meaning And Richness To Life—Really!
I believe there are other profound cold therapy benefits that are hard-to-quantify. Starrett contends that your cold exposure practice can serve as a good barometer for your state of recovery and desire to train. He asserts that sore, stiff, or poorly functioning muscles seem to be more sensitive to cold exposure, and that if you’re in a fatigue/overtraining rut, your tolerance to cold diminishes accordingly. K-Starr notices that when he’s fried from big workouts or stressful travel, the cold water stings and he wants out quickly. When he’s less stressed and more rested, he has no problem relaxing in there for up to eight minutes. Remember, he’s jumping right into a dry sauna. As Brian described, your exposure times can increase when you have access to a sweet contrast setup.
Starrett’s “desire to train” concept deserves further appreciation. In his set of exclusive video interviews in the Primal Endurance Mastery Course and the Keto Reset Mastery Course, he references studies with athletes suggesting that a subjective “desire to train” score is a more accurate indicator than any of the modern high tech biofeedback metrics like Heart Rate Variability, pulse oximeters, blood lactate meters, sleep cycle apps and all the rest. As an old timer whose endurance exploits predate even heart rate monitors, I strongly agree that your intuition, mood and motivation level should take center stage for making workout decisions, especially when it’s time to downsize grand ambitions. I know that when I take a few moments to sit quietly and reflect on my planned workout, sometimes profound insights occur, and I roll over and go back to sleep. Ditto for when I hesitate to jump into a routine cold shower or pool plunge (or get out earlier than usual)—it’s a reliable indicator that I’m overstressed or overtired.
Furthering Brian’s comments about the mood elevating effects of cold therapy, I’d also suggest that cold exposure helps improve your focus, confidence, and mental resilience—particularly since you will improve your tolerance and appreciation over time—and that these benefits will carry over into all other areas of life. Lift heavy things, sprint once in a while, get adequate sun exposure, plunge into cold water—these are all hormetic stressors that help you bring your A-game to everything you do. I’m not saying sitting in a chest freezer every morning will help you muster the courage to ask for a promotion, commit to enter an adventure race, or ask for a date with that certain person in the office, but it might help….
If you’re content to spend almost all 24 daily hours in a climate controlled home, car, and office, enjoy the wholly modern luxury of a hot shower a couple times a day, and never voluntarily subject yourself to the beautiful moments of discomfort like a cold plunge, the final few reps of a tough set in the gym, or the final few miles of a tough session on the roads, that’s fine. We can still be friends. But as many of us living Primally can attest, there are benefits to challenging the perceived limits of mind and body in order to stimulate peak performance and happiness. Sir Roger Bannister, the legendary first sub-four minute miler who passed in March at age 88, offered up a memorable quote in his 1954 biography, The Four Minute Mile: “Struggle gives meaning and richness to life.” One thing’s for sure after you try it out: you will appreciate a warm shower or a warm bed like never before.
Does Cold Exposure Stimulate Fat Reduction? Mehhh…
You may have heard exciting news about something called Brown Adipose Tissue (aka BAT, or brown fat), a special type of adipose tissue that has a different role in the body than the fat that accumulates across the body when you store more calories than you burn; this stuff is known as white adipose tissue. Instead of just storing calories like white fat, brown fat is also able to generate heat to help maintain the body’s ideal core temperature. Infants have lots of brown fat for extra protection. Brown fat levels dwindle as we age, and interestingly, obese people have lower than normal levels of brown fat.
The excitement about brown fat emanates from research showing that cold exposure spurs a fifteen-fold increase in brown fat activation. It’s theorized that this increase in cellular activity in brown adipose tissue can help stimulate the burning of additional white fat, making cold exposure an effective weight loss catalyst. The idea here is that the caloric energy your brown fat generates for rewarming will be burned instead of otherwise stored as white fat.
Research is not conclusive in the brown fat area, and scientists assert that it’s very difficult to measure the effect of environmental temperature on metabolism. It’s virtually certain that getting cold and then forcing yourself to warm naturally (no saunas or hot showers allowed!) will boost metabolic rate. However, I’d hesitate to put this in the forefront of fat reduction techniques. Even as drug companies are spending millions to unlock the power of brown fat (via cold exposure or drug-related means) to burn white fat, I’ll argue that ditching grains, sugars and refined vegetable oils to minimize insulin and boost fat metabolism might be a much better area of focus. What’s more, there is a logical counterargument that cold exposure might stimulate a corresponding increase in appetite that would counteract any potential fat reduction benefits. This makes sense along the lines of the compensation theory of exercise, detailed in a recent post about Rest and Recovery.
Ray Cronise, a former NASA materials scientist who oversaw Space Shuttle experiments and has been a prominent voice in progressive health circles for the past decade, has performed some increasingly sophisticated experiments that suggest the potential of cold exposure to boost fat loss. Cronise lost a remarkable 27 pounds in six weeks with a regimen of cold showers, talking neighborhood walks while purposely way underdressed, and sleeping with open windows and/or little or no covering. Cronise’s experiment was inspired by that infamous viral news story about Olympic swimming legend Michael Phelps eating 12,000 calorie per day that I discussed in the recent Sami Inkinen post. Doing some basic metabolic calculations, Cronise speculated that Phelps was eating vastly more calories than he burned during his intense workouts, and that hence a significant portion of his caloric expenditure must be going toward maintaining his core temperature while spending hours in the water.
Tim Ferriss brought more attention to Cronise’s work and the concept of burning off brown fat through cold exposure when he covered the matter in his bestseller, The Four Hour Body. Google brown fat and you will find assorted chatter jumping to the conclusion that brown fat stimulation promotes weight loss, but the hard science is just not there—yet anyway. For now, I wouldn’t put much emphasis on cold exposure for fat loss, and instead be content to enjoy the many other benefits of cold therapy.
Nothing left to say but get yourself a chest freezer (another chest freezer?) and get started! Let me know what you think, and thanks for stopping by today.
Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.