I’ve developed a long-term relationship with cold stress. My early experimentation started in the winter of 2012 when I began taking very cold showers.
Cold is not your friend, yet it can help you become more resilient. Cold exposure is unappealing and unpopular. It is only used by the very few. But, why is that?
Because (imho) when cold exposure leads to shivering thermogenesis it may make you feel miserable. And this requires you to step out of the coziness of your comfort zone. You could now see the unsurprising incompatibility between the average Joe (most people) and cold stress.
In the short term, acute cold exposure has been shown to increase the production of norepinephrine (read along), increase alertness and heat production – thermogenesis -, increase energy expenditure, modulate immune system activation, alleviate pain – to name a few. If it involves shivering, these effects are intensified. Still to be explored are the connections between cold thermogenesis and vagus nerve activation. To see the potential benefits of vagus nerve activation, head over to Scholar or Pubmed and do a search of the medical databases.
With many of my self-experiments I like to go to the extremes. Cold does not make an exception. One of the protocols that I’ve extensively experimented with was to take long very cold showers immediately after strenuous heavy lifting. It helped with recovery – or so I think. I’ve been doing it on a consistent basis over the last 2 years.
Few months ago, I took this a step further. Immediately after my workout I would jump straight into an IR (infrared) sauna (heat shock) for 5-7 minutes followed by a cold shower for another 5-7 minutes (cold shock). To be honest, I was a bit reluctant and hesitating at first. I mean, this is not something most rational people would do…
Anyway, in my desire of knowing more about the implications of cold exposure on exercise, recovery, and overall health, I came to reading a report on cold thermogenesis (CT) from Dr. Rhonda Patrick , a researcher who I admire much. Following some of the studies in her report and continuing with my own research, I came across a few articles stressing that immediate post-workout cold exposure could blunt the positive pro-inflammatory effects of exercise. The critical window when you should not interfere with this inflammatory response, they proposed, is 1 hour.
This got me thinking…Moreover, it gave me a different strategy to develop and experiment with. It gave a child a new toy.
I purposed to stop doing CT right after lifting and observe the impact it would have on my strength progression, as well as on my recovery from the workout. Of course, I would not stop doing CT altogether. I would just push it for later in the day or only doing it only on non-workout days.
My current approach: lift + IR sauna (5-7 min.) + warm shower. It’s still too early to report on my results.
So, in this post I want to elaborate on the findings of Dr. Patrick as well as on my own short review of a couple of studies. Here, we deal with whole body cryotherapy, cold water immersion, and local ice application in the context of anaerobic exercise, pathology, as well as health optimization.
Whole Body Cryotherapy and Cold Water Immersion
Let’s begin with the context of exercise induced inflammation. As per Dr. Rhonda Patrick:
There is an anti-inflammatory response to this inflammation which begins to peak about 1 hour after exercise. At this point, some of the anabolic hormones such as IGF-1 that are increased with the immune activation seem to also return to pre-exercise levels around 1 hour post-exercise. These anti-inflammatory cytokines help keep our immune system from going overboard. They modulate the activity of the immune cells, preventing them from causing excessive tissue damage. 
In short, there is an anti-inflammatory response to exercise induced inflammation that is at its highest around 1 hour post-workout. You may not want to mess with it if you want to reap the bulk of the benefits that exercise gives you. But, does this apply to everybody? Is it valid for both aerobic and anaerobic training?
Before exploring potential answers to these questions, let’s try to get a better understanding of inflammation in the context of exercise:
One study wanted to determine to what extent and by which time course prolonged strenuous exercise influences the plasma concentration of pro-inflammatory and inflammation responsive cytokines as well as cytokine inhibitors and anti-inflammatory cytokines. 
They recruited 10 male subjects who completed the Copenhagen Marathon of 1997 (an average of 3 hours and 26 minutes run). They’ve taken blood samples before, immediately after, and then every 30 minutes for the next 4 hours. They measured: TNF-alpha, IL1-beta, IL6, IL1-ra, sTNF-r1, sTNF-r2 and IL10.
– highest IL6 – immediately after race – 128-fold increase (compared to pre-exercise levels)
– highest IL1-ra – 1h after the race – 39-fold increase (compared to pre-exercise levels)
– IL10 – immediately after race – 27-fold increase
– IL1-beta, TNF-alpha, sTNF-r1, sTNF-r2 – peaked in the first hour post-exercise.
In conclusion, strenuous exercise induces an increase in the pro-inflammatory cytokines TNFα and IL-1β and a dramatic increase in the inflammation responsive cytokine IL-6. This is balanced by the release of cytokine inhibitors (IL-1ra, sTNF-r1 and sTNF-r2) and the anti-inflammatory cytokine IL-10. The study suggests that cytokine inhibitors and anti-inflammatory cytokines restrict the magnitude and duration of the inflammatory response to exercise. 
Would cold exposure lead to cytokine inhibition if applied immediately after exercises? I suspect it would, but I think it widely depends on the context and the type of exercise. In this case we were dealing with prolonged endurance exercise (aerobic training). But what happens in the context of anaerobic training?
In another study published in the European Journal of Applied Physiology in 2009, researchers wanted to determine the impact of cold ice-pack application post sprint-interval training (anaerobic exercise) on the balance between:
– anabolic factors – GH, IGF-1, testosterone
– catabolic factors – cortisol, IGFBP-1
– pro-inflammatory cytokines – IL6, IL1
– anti-inflammatory cytokines – IL1-ra. 
Twelve males, elite junior handball players performed 4 250 m treadmill run, at 80% of each individual’s maximal speed, followed by a rest period with and without local cold-pack application. 
They’ve taken blood samples before, immediately after, and at 1 hour post-exercise (recovery). They found that exercise induces significant increases in IL6, GH, testosterone, and IGFBP-3. Applying cold-packs to their hamstrings for 15 minutes post-workout led to a significant decrease in IL1, IL1-ra, IGF-1, and IGFBP-3 and a greater increase in IGFBP-1 in the recovery period. In their own words:
Local ice therapy immediately following sprint-interval training was associated with greater decreases in both pro- and anti-inflammatory cytokines and anabolic hormones supporting some clinical evidence for possible negative effects on athletic performance. 
When deriving insight from this study you have to acknowledge the small sample size (n=10), the fact that there was no separate control group, the fact that local-cold-pack application for 15 minutes may not elicit similar responses to longer duration whole body cold exposure, and so on and so forth. Here are some numbers that you can compare to the previous study ():
A somewhat solid take-away message from these two studies, as suggested by Dr. Rhonda Patrick , is that there is an anti-inflammatory response to exercise induced inflammation that peaks 1 hour post exercise and that you may not want to interfere with it.
A good question to ask then is what happens when you apply cold exposure after the critical 1 hour period post-exercise. Are you still interfering with the proposed pro/anti inflammatory balance? Would this be a positive intervention?
A potential answer comes from another study. Fonda and Sarabon (2013)  investigated the impact of WBC (whole-body cryotherapy) on biochemical, pain, and performance parameters during the 5-day recovery period after damaging exercise for hamstrings.
In this case, the sample size was still low (n=11, healthy young male adults) but the design of the study was better compared to the above. Here we are dealing with a cross-over study:
Subjects randomly assigned to 2 groups:
– 1 group of WBC, 1 group of control (first session).
After 10 weeks (second session):
– the control group from the 1st session is now switched to doing WBC, while the WBC group of the 1st session was now the control group.
Participants completed a bout of damaging exercise for the hamstring muscles on two separate occasions (control and experimental condition) separated by 10 weeks. During the control condition, subjects received no treatment after the damaging exercise. The experimental condition consisted of WBC everyday during the recovery period. WBC included single 3-min daily exposures to low temperatures (-140 to-195 °C) in the cryo-cabin. During the recovery period, subjects were tested for biochemical markers, perceived pain sensation, and physical performance (squat jump, counter movement jump, maximal isometric torque production, and maximally explosive isometric torque production).
Majority of the observed variables showed statistically significant time effects ( P < 0.05) in control group, which indicates the presence of muscle damage. Significant interaction between the control and WBC condition was evident for the rate of torque development ( P < 0.05). 
Researchers reported substantially different pain and performance measures between the two groups after exercise. The experimental group (WBC) showed performance improvements for up to 3 days after the cryotherapy session, as well as an improvement in their pain measures.
As Dr. Patrick points in her cold stress report , the next good question to ask would be: what happens if you do cold exposure immediately after strength/resistance training?
A possible answer comes from a study published in the Journal of Physiology in the summer of 2015. Here, a group of researchers explored molecular, morphological and functional adaptations to strength training and CWI (cold water immersion) through two studies.
– 21 physically active men did strength training twice a week for 12 weeks
– subjects did CWI for 10 minutes or active recovery (ACT) after each training session.
Strength and muscle mass increased more in the ACT group than in the CWI group (P < 0.05). Isokinetic work (19%), type II muscle fibre cross-sectional area (17%) and the number of myonuclei per fibre (26%) increased in the ACT group (all P < 0.05), but not the CWI group. 
– 9 active men did single-leg strength exercises on separate days, followed by CWI and ACT
– researchers collected muscle biopsies before, at 2, 24 and 48 hours after the training session.
The number of satellite cells expressing neural cell adhesion molecule (NCAM) (10-30%) and paired box protein (Pax7) (20-50%) increased 24-48 h after exercise with ACT. The number of NCAM(+) satellite cells increased 48 h after exercise with CWI. NCAM(+) – and Pax7(+) -positive satellite cell numbers were greater after ACT than after CWI (P < 0.05). Phosphorylation of p70S6 kinase(Thr421/Ser424) increased after exercise in both conditions but was greater after ACT (P < 0.05). 
These data suggest that CWI attenuates the acute changes in satellite cell numbers and activity of kinases that regulate muscle hypertrophy, which may translate to smaller long-term training gains in muscle strength and hypertrophy. The use of CWI as a regular post-exercise recovery strategy should be reconsidered. 
And more simply put:
They think that long term muscle and strength gains are attenuated by cold water immersion (I assume they refer to CWI done immediately post exercise) and they propose that folks who want increase strength, recover from injury or maintain their health should therefore reconsider whether to use cold water immersion as an adjuvant to their training. 
This makes me wonder about the meaning of ‘maintain their health’ and also why ‘recover from injury’ is not put into a time perspective. On another note, Adel Moussa from Suppversity shares his perspective on this study. He goes into more details, so if you want to read it, go here.
In her report Dr. Patrick  makes some powerful statements:
Basically, if you were looking to make the argument that cold stress, especially cold-water immersion, should be avoided after strength training, this last study mentioned would be your holy grail. Not just because of the compelling results that the authors demonstrated, but also because they cited other studies that showed similar results with respect to cold exposure and hypertrophy, including some that employed clever investigative methods like having participants do hamstring curls but only immersing one leg in cold water and then going on to measure the difference in hypertrophy between legs afterwards.
I would be more cautious in making such claims and more focused on investigating the intricacies of each of the ‘other’ studies with similar findings provided by the researchers. It may be wiser not to take anything for granted.
To her credit however, Dr. Patrick comes to her senses and reflects good critical thinking practices:
So that leaves us with a few open questions, but the most important one is this: would we still have seen blunted or reduced hypertrophy from training if cold-water immersion was done at literally any point other than immediately after strength training?
I don’t know the answer definitively because no study has investigated this yet, but it’s an area I hope future studies will illuminate for us, especially in light of the fact that the occasional cold stress seems to have the possibility of conferring benefits in many other respects. 
As she points out from the research she analyzed (and I presented here), the first hour post-strength-exercise seems to represent an anabolic window and it should be prudent for folks to exercise caution in timing cold exposure practices, should they decide to use any.
Some More Thoughts
I would propose detailed consideration if one decides to use cold exposure in the context of exercise. In designing a good strategy, there are many variables to account for, including, but not limited to: type of exercise, type of cold exposure, duration of exposure, frequency, health parameters of the subject, timing, and many others.
Leaving aside cold exposure and exercise, we should be aware of the other numerous potential therapeutic and non-therapeutic advantages of subjecting yourself to cold stress. Many studies investigate the potential use of cold exposure in pain alleviation and immune system modulation.
For example, one study compared winter swimming and cryotherapy by following two groups of healthy females (n=10, each) for 12 weeks. One group did winter swimming (0-2˚C) for 20 seconds, three times a week, while the other group did whole body cryotherapy (-110˚C) for 2 minutes, three times a week.
Blood specimens were drawn in weeks 1, 2, 4, 8 and 12, on a day when no cold exposure occurred (control specimens) and on a day of cold exposures (cold specimens) before the exposures (0 min), and thereafter at 5 and 35 min. 
They found that plasma ACTH and cortisol in weeks 4–12 on time-points 35 min were significantly lower than in week 1 and speculated that this may be due to habituation and that neither winter swimming nor whole-body cryotherapy stimulated the pituitary-adrenal cortex axis. They saw no change in plasma epinephrine in both experiments; however, norepinephrine showed significant 2-fold to 3-fold increases each time for 12 weeks after both cold exposures. . They also looked at IL1-beta, IL6, and TNF-alpha and saw no changes after cold exposure.
These findings are very different from the ones above. It should make one think about the significance of exercise to the results, as well as its effect on pro and anti-inflammatory marker dynamics.
In another study published in Plos One journal in 2012, researchers investigated whole body cryotherapy as a strategy to improve antioxidant capacity in healthy men. 30 young, healthy male subjects (BMI 22 – 33) were exposed for 3 minutes to cryogenic temperatures (-130˚C) everyday for 20 days.
Blood samples were obtained in the morning before cryostimulation, again 30 min after exposure and the following day in the morning, during the 1st,10th and 20th session.
The obtained results indicate that cryogenic temperatures in repeated daily treatments result in changes in the peroxidant and antioxidant status. These changes seem to depend on the number of cryostimulations. After 20 daily treatments there was an increase in SOD, SOD:CAT ratio, a decrease in the concentration of reduced and oxidized glutathione and in the activity of GPx. 
They report an increase in ROS production as a result of WBC and they think that this response is accompanied by compensatory adaptive changes. Do I hear the word hormesis?!
Further on, some technical arguments to the dynamics of the oxidative/anti-oxidant system:
SOD activities appear sufficiently high and relatively uniform across tissues, suggesting that the removal of superoxide anion may not be a rate-limiting step. In comparison, GPx destroys the end products of the ROS generation pathway and its activity is relatively low . Increased glutathione reductase activity in subjects with normal BMI and absence of this reaction in people with elevated BMI may suggest the influence of a factor released from adipose tissue that inhibits enzyme activity or synthesis. It is worth noting that these differences become clear only after the continuation of 20 WBC treatments. 
So, the subjects with the BMI toward the end of the spectrum (33, for this study) did not experience the same increase in glutathione reductase (GSR) as those with lower BMI? This is interesting. But, what is GSR responsible for?!
It is a central enzyme of cellular antioxidant defense, and reduces oxidized glutathione disulfide (GSSG) to the sulfhydryl form GSH, which is an important cellular antioxidant. 
Similarly, there were some interesting findings with respect to uric acid secretion:
The concentration of uric acid decreased after 10 WBC sessions but then significantly increased after the series of 20 WBC sessions, with a simultaneous decrease in plasma albumin and ceruloplasmin. It seems that the oxidant species produced during the first stage of WBC treatment (confirmed by a significant increase in 8-Iso-P) induces uric acid consumption. The results of the presented studies indicate a significant role of uric acid as a principal antioxidant molecule in the human body. 
For my current experimentation protocol, I will still use cold thermogenesis but not immediately after strenuous resistance training. I will push cold exposure to later in the day or even doing it only on non-workout days, or something in-between.
I experimented with whole body cryotherapy in the past. As dramatic as it may be marketed, the exposure to very cold air (-100 to -200˚C) for up to 3 minutes/session pales into comparison with prolonged very cold water immersion.
CWI still remains the most intense, less tolerable, and most miserability-inducing CT strategy (ice baths > 10 minutes long). And these effects are being accentuated with the onset of shivering thermogenesis. It still surprises me that I get the same immediate alertness, huge mood enhancement, and acute explosion in energy levels even after 3 years of doing prolonged cold water immersion.
WBC seems like child’s play compared to CWI. And it appears that I am not the only one reporting this:
Tolerance of cold in the cryogenic chamber with very low humidity is higher than during immersion in cold water, which may have a temperature of about 4˚C during the winter season. 
I hope that by now you see the importance of putting everything into perspective and within the appropriate context. Controlling for as many factors and variables as possible is crucial when deciding to implement a certain (any) strategy in your life. Reductionist and generalist approaches to nutrition, weight-loss and wellbeing are nothing but short-sighted.
They become even more myopic when you include genetics and epigenetics into the equation, an equation that makes a massive call to modern medicine to steer away from unsupported and outdated general advice to personalized interventions, where every person requires their own n=1 approach.
To end on a cold note, I leave you with a line from Wim Hof, probably the most experienced person on Earth when it comes to cold exposure:
Cold is a merciless, but righteous teacher.
- Dr. Rhonda Patrick (2016). Cold Stress Report. Retrieved from http://foundmyfitness.com/?sendme=cold-stress
- Ostrowski, K., Rohde, T., Asp, S., Schjerling, P., & Pedersen, B. K. (1999). Pro‐and anti‐inflammatory cytokine balance in strenuous exercise in humans. The Journal of physiology, 515(1), 287-291.
- Nemet, D., Meckel, Y., Bar-Sela, S., Zaldivar, F., Cooper, D. M., & Eliakim, A. (2009). Effect of local cold-pack application on systemic anabolic and inflammatory response to sprint-interval training: a prospective comparative trial. European journal of applied physiology, 107(4), 411-417.
- Fonda, B., & Sarabon, N. (2013). Effects of whole‐body cryotherapy on recovery after hamstring damaging exercise: A crossover study.Scandinavian journal of medicine & science in sports, 23(5), e270-e278.
- Roberts, L. A., Raastad, T., Markworth, J. F., Figueiredo, V. C., Egner, I. M., Shield, A., … & Peake, J. M. (2015). Post-exercise cold water immersion attenuates acute anabolic signalling and long-term adaptations in muscle to strength training. The Journal of physiology, 593(18), 4285-4301.
- Leppäluoto, J., Westerlund, T., Huttunen, P., Oksa, J., Smolander, J., Dugué, B., & Mikkelsson, M. (2008). Effects of long‐term whole‐body cold exposures on plasma concentrations of ACTH, beta‐endorphin, cortisol, catecholamines and cytokines in healthy females. Scandinavian journal of clinical and laboratory investigation, 68(2), 145-153.
- Lubkowska, A., Dołęgowska, B., & Szyguła, Z. (2012). Whole-body cryostimulation-potential beneficial treatment for improving antioxidant capacity in healthy men-significance of the number of sessions. Plos one, 7(10), e46352.
- GSR – Glutathione Reductase [Homo Sapiens (human)]. Retrieved from NIH.gov.
Images: adapted from here and here.