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Post-workout ice baths are one of those things that everyone believes in, no matter what the science says. There have been a bunch of ice bath studies, but they’ve used lots of different water temperatures, immersion times, and outcome measures, and the results have been very mixed. This month’s European Journal of Applied Physiology has a study from France’s National Institute of Sport that looks like the strongest evidence yet in favour of ice baths — and offering some concrete advice on water temperature and immersion time.
One key difference from previous studies: they used elite athletes — 41 football, rugby and volleyball players — whose recovery might be expected to be faster than untrained volunteers. They tested four different protocols:
- TWI: body-temperature water (36 C) for 15 minutes;
- CWI: cold water (10 C) for 15 minutes;
- CWT: contrast water (10 C and 42 C), alternating 90-second bouts for 15 minutes;
- PAS: no water — just sitting there for 15 minutes.
The exercise they used to induce fatigue and muscle damage was alternating bouts of hard rowing and counter-movement jumps. They took blood samples and tested muscle strength (MVC), jump height, and power produced during 30 seconds of rowing — and they did those tests before and immediately after the exercise, then again one hour and 24 hours later.
As you can imagine, with all those different test groups and protocols, the results are a bit of a jumble. The key result, as far as I’m concerned, is right here:
This is the data for creatine kinase, which is a commonly measured marker related to muscle damage. Its exact significance is often debated, but the authors of this study suggest it’s a sign of “reduced passive leakage from disrupted skeletal muscle, which may result in the increase in force production during ensuing bouts of exercise.” The key: the ice bath outperforms all the other interventions, including the contrast bath.
Of course, nothing is quite that simple. If we look at the performance measures, the picture gets muddier:
What we’re interested in here is the cases where performance returns to “normal” quickly. The asterisks indicate where performance is reduced from the first bout by a statistically significant amount. The broad conclusion we can draw is that both the ice bath and the contrast bath seem to offer some advantages compared to room temperature water or not bath. The main reason I included this data is to show that it’s not a simple, magical effect. It’s complicated. But for practical purposes, this data gives me more confidence than any previous study to support the very strong anecdotal evidence that a sustained cold-water bath — in this case, 15 minutes at 10 C — helps to speed up recovery after hard workouts.
It also seems like it is better to do nothing if you are not going to use the 10c water. The other methods produce a worse recovery than just resting for 15 minutes. Is that your opinion too?
How about adaptation instead of recovery? If inflammation is part of the body’s adaptation response to stress then ice may limit adaptation. It would be interesting to see a study of athletes’ improvement over two weeks on different recovery protocols.
@Rich They’ve done those studies. And they show exactly what you would expect. Ice baths absolutely limit the body’s adaptation. The same logic is now being applied to anti-oxidants and several other “recovery aids.” Faster recovery is not necessarily a good thing. “How fast you recover” is pretty meaningless. “How fast (or to what extent) you get bigger/faster/strong/fitter” is what athletes really care about. In other words, we are not at all interested in when performance returns to “normal.” We are interested n when performance improves. At least, that’s what I am interested in. It is a totally untrue statement to say “everyone believes in ice baths.” There is compelling science that explains precisely why you do NOT want to ice. And the summary is exactly what you, Rich, wrote. Your body responds to stimulus (aka inflammation/stress). Remove that, and you remove the stimulus to adapt.
@John: Yes, there’s not much point to room-temperature water baths, and straight cold water seems to outperform contrast baths. This study only tested one particular configuration of contrast baths — other studies have found that longer contrast periods (e.g. 5 min) seem to perform better: if you’re only staying in the cold water for 90s at a time, you’re probably only cooling your skin rather than penetrating into the flesh. Still, I’ve never bothered with contrast baths.
@Rich and @Jordan: Yes, one of the biggest themes in current sports performance research is trying to understand the balance between adaptation and recovery, though this research is still very much in the early stages. Antioxidants in particular have been shown to block some of the gains of training (though not in all studies), presumably by suppressing the “harmful” free radicals that actually signal to the body that it needs to adapt. The “train low, race high” nutrition theory is another example of this kind of thinking: training with low carbohydrate stores frees up cell signalling proteins that would otherwise be locked up in glycogen stories in your muscles. And anti-inflammatories are another good example: I wrote an article about that dilemma last year.
And yes, ice baths is another example, though it remains controversial. I actually haven’t seen those studies showing that ice baths limit adaptation, so I’d love to get a reference so I can read them. The English Institute of Sport has done a lot work in this area — but even they don’t advocate completely eliminating ice baths. The British policy for 2012 Olympic hopefuls is that they shouldn’t take ice baths during base training, when adaptation is the focus, but they should take ice baths during competition phases, when recovery is most important. Ultimately, the big buzz word these days is periodization — not just of training, but of nutrition and recovery modalities.