"Never be limited by other people's limited imaginations. If you adopt their attitudes, then the possibility won't exist because you'll have already shut it out." -Mae Jemison, astronaut

Sunday, February 2, 2014

Believe and You Will be Healed!

I have been meaning to finish my research into heat acclimation/acclimatisation and blog on that, but since we're so well and truly into summer here in Western Australia, with 10 days above 35 degrees in January, it seems a bit late!

Thus, it's more fitting to talk about ice baths! :-)

Or more appropriately, "cold water immersion" (CWI). I, myself, have had no less than three ice baths (CWI experiences) this week. Essential to me, as I've also just finished my highest mileage training week ever, hitting 165km + 4400m. Woohoo! Feeling good.
Canadian mountain rivers are NOT 14 degrees!

I've been aware of cold water recovery methods since I started running trails in 2006, watching my trail running buddies in Canada happily jumping into near-frozen streams in the mountains after long runs. A few years ago, I received a lovely phone call from a fellow who spent a lot of time helping Helen Stanger (AUS) train through her incredible ultra career. He asked, "Do you use ice baths for recovery?" and went on to state how important he felt they were for Helen. Last year, being "bathtub-less", I bought a large bin and started having some ice baths outside. I threw a thermometer into the water often, as I had it in my head that I should aim for 10-12 degrees.

But despite all the anecdotal reports from athletes raving about their love of ice baths, research has been quite contradictory. I decided to delve into it.

The main problem with the research is that it's all over the place. Immersion in water ranging from 0 degrees Celsius to 24 degrees Celsius. Full body immersion vs legs-only. Five minutes vs 20 minutes. Men vs women. Trained athletes vs novices. Winter swimmers vs rugby players. And test exercises that are commonly used as a way to measure "recovery" include eccentric muscle contractions with weight (e.g., using the quad). Hardly a practical application for most athletes. And these recovery "test" exercises are administered anywhere from 5 minutes after CWI to 24 hours after. No wonder we can't make sense of whether ice baths are good for us or not.

Pre-bathtub days, when I had to feed mossies, too
In one review (Beakley and Davison, 2009, Br J Sports Med, 44, 179-187), the authors report on what happens to our bodies when we immerse them in cold water. The stuff that's not so good - "cold shock." Increased heart rate, increased blood pressure, increased respiration, increased cortisol, decreased cerebral blood flow (a few people nearly passed out at 0 degrees), and oxidative stress. So why would we do it? Because the apparent benefits include vasoconstriction (constricting blood vessels), which should help remove metabolic waste from legs, decrease swelling/oedema and inflammation, and decrease muscle soreness. It reduces our core temperature, which gets us recovered and ready for exercise again sooner. Even the hydrostatic forces - the pressure of the water - pushes body fluid from the periphery to the core, which increases central blood volume. And cold water/ice has an analgesic effect. Who doesn't like a little numbing? :)

What I've taken from the research indicates this:

  • Water temperature of approximately 12-14 degrees Celsius may be optimal. Colder, and anything approaching 0-5 degrees Celsius, induces too much stress. Just like most everything in life, moderation is key. Running is good, but too much running results in overtraining and injury. CWI is good, but too cold results in shock. One should not have a "shivering" response, as evidence indicates it's associated with free-radical production. 
  • Immersion for 10-20 minutes appears optimal, at the temperature above.
  • Training/racing should not be expected to be undertaken immediately afterwards, as cold muscles will have compromised contraction abilities and slow nerve conduction speeds (several studies had subjects "test" immediately after CWI). Core body temperature will naturally rise to baseline within 24 hours. It may be possible to speed this up with a warm shower (the idea of "contrast water therapy," which I won't go into).
Stream crossing mid-run. It really IS hard to move after this kind of CWI.
  • Your belief in the power of CWI makes a difference. Cook and Beaven's (Br J Sports Med, 2013, 47, 705-709) novel study on CWI at 14 degrees for 15 minutes (vs other options) found that the rugby players who "liked" the ice bath had better sprint performance the next day than those who didn't. So, the ice bath helped, BUT believing in the ice bath appeared to help even more. Believe, and you will be healed! Use the placebo effect to your advantage, as it can also trigger your brain's "reward centre," which can then cause your body to dump some nice opioids into your system. Mmmmm, endogenous opioids....
  • Immerse only over the hips. Do not immerse the "core" area including the major organs such as heart and lungs. There is no evidence of benefit to runners/athletes generally in doing this and it looks to bring more potential for harm/shock.

Finally, prepare adequate reading material, such as your favourite ultra running magazine, and ensure no small, impressionable children are nearby as you take that first step into the tub!


  1. So the frozen water under the ice in South Korea that the Amazing Race contestants had to try and stay in might be a shock to the system and have negative effects?, and if I tell my brain that the cold water will help me, the brain will feel happy because I've told myself its good for me says those 2009 and 2013 researchers.

    The title "believe and you will be healed" reminds me of things like http://www.esvbible.org/Matthew+8%3A8-13/ Matthew 8:13 where Jesus the Christ told a Centurion to believe and healing will occur, but one of the misunderstandings that the tele-evangelist "faith-healers" and others make (deliberately? so as to make money from gullible/naive/poorly educated but often very needy people), is that while Jesus was asking people to show trust in his ability as part of the Triune God (maker of all things and holding everything together NOW, so in control of hydrostatic forces and everything else that works in a consistent pattern in the universe) to be able to override, or fix negative patterns in the body with supernatural healing intervention in those patterns, it was NOT the "positive belief" or placebo trust, or "amount of faith/trust/belief" that resulted in them being healed, it was still the work of God the Son/The Christ/Jesus making the healing intervention. Its just that he wanted them to trust him and be positive mentally/become friends towards him before he would do the healing intervention. Maybe the why of that is that God wants our trust and friendship before he will work with us. He may not help us as much or at all, if we don't trust him and make friends with him, obey our Maker. Exactly how Jesus intervened to heal people we don't know for sure, although these days those with sufficient medical knowledge we could guess a bit. In the same way maybe we don't fully understand "the how" CWI works, but the anecdotal results suggest it does when used the right way. Further exploration of why and how is needed. Icepacks are used routinely to reduce inflammation, as is cryotherapy in hospitals just as compression gear has been used in hospitals against inflammation for decades. As you say " apparent benefits include vasoconstriction (constricting blood vessels), which should help remove metabolic waste from legs, decrease swelling/oedema and inflammation, and decrease muscle soreness"... "reduces our core temperature, which gets us recovered and ready for exercise again sooner. Even the hydrostatic forces - the pressure of the water - pushes body fluid from the periphery to the core, which increases central blood volume. And cold water/ice has an analgesic effect. Who doesn't like a little numbing? :)" so it seems there has to be potential for significant and varied benefits from the hips to the toes...

  2. .Other studies have suggested that by reducing inflammation after hard efforts you lose some of the rebuilding effects which inflammation/elevated temperature stimulate long-term...Which suggests that overuse of CWI may actually retard postive muscular training gains?...So some questions still to be answered in terms of best use, and moderation, occasional use may be more the right track than CWI after every hard training session and race, maybe a bit of informed picking and choosing when to use CWI and when not to taking into account peak races, and training cycle position???? I got to stand in a cold pool after the 2012 Gold Coast Half for 10min I think the temp was about 5-10degrees... and maybe at the moneghetti camp in the river also... My coach used to drill into me in the late 80's as a teen to "get straight into a warm shower, don't get cold" after long training walks, which at first thought seems contradictory, but as you seem to briefly mention ("contrast water therapy"), maybe this is just taking a different approach/route/option. I think because there is elevated body core temperature when racing or training for a long period of time, when you stop the body cools down quickly (especially if the local temperature is low), so the core (and the organs etc) can have a rapid drop in temperature which is not healthy...so a warm shower (or a jumper/warming clothes etc) soon/immediately after can ensure the core temperature does not drop as rapidly and the body core temperature settles without rapid change (and the associated cold shock type negative effects)...??? Where as the cold water route/option is more focused on the primary muscles used in running from the hips down to the toes, and fast-tracking the rebuilding process in the muscles from post race state to ready to go again state... After the 2011 Melbourne Marathon me and the other "elite" runners (I use the term "elite" very loosely referring to me and maybe some of the others) saw the ice-baths that were used by the Collingwood and Geelong players in the 2011 AFL Grand Final under the MCG...

  3. My "gut feeling" (informed guess I hope) is that coldness (water or just cold air etc) in the right temperature range appears to have a lot of post-race benefits (as does warmness e.g. warm shower or CWT but perhaps to a lesser extent), but that further study would be helpful, especially focused on ultra runners and/or marathon runners, 10k/half marathoners??? If I was a post grad in Sports science (I was an undergraduate more than a decade ago, and even did one post-grad unit (advanced biomechanics)) or Human Movement or Exercise Science or related disciplines of study then a thesis and lots of good studies on this subject could be a good thing to try and move beyond anecdotal and plausible, plus further deal with some of the paradoxes, and apparently contradictory studies on this subject? To get to exactly why and how CWI post race strategies can be good in more detail might be good...