Taking an ice water bath after a strenuous workout is a common practice not only among elite athletes but also with amateurs; in an effort to try to recover faster, and reduce (if not prevent) muscle pain and soreness.
From Ironman World champion Craig Alexander, to professional rugby players and marathoners, the after-workout ice bath has become a standard practice routine.
Before embarking in this rather “unpleasant” experience it's important to know the benefits and the side effects of it.
Why taking ice baths?
The theory behind the ice baths practice is connected to the fact that while exercising, you cause small tears in the muscle fibers (called microtraumas).
This damage stimulates muscle cell activity; and while repairing fibers, the muscle also becomes stronger.
However, the repairing process causes the so-called stiffness; that in scientific terms is referred to as Delayed Onset Muscle Pain and Soreness (DOMS).
Generally DOMS occurs between 24 and 72 hours after exercise.
Cold baths (also known as cryotherapy) should reduce muscle inflammation and its ensuing effects. In particular:
- constrict blood vessels and flush waste products (e.g., lactic acid) out of the affected muscles;
- reduce swelling and tissue breakdown; and
- decrease metabolic activity and slow down physiological processes.
After the cold bath, the increased blood flow speeds circulation, and this, in turn, is said to improve the healing process.
Which temperature and for how long?
Even though there are no official guidelines as to ice baths’ temperature and time; most trainers and athletes recommend a water temperature between 54° to 59°F (i.e, 12° to 15° Celsius). The immersion time should be of 5 to 10 minutes (even though, consensus seems to be at 8 minutes).
Does it really work?
Until recently, almost all of the studies I found offered inconclusive or contradictory findings on this topic.
A new systematic review of cold water immersion interventions has been published in the issue 2, 2012 of The Cochrane Library.
This time around the researchers wanted to assess the strength of clinical evidence about how well cold water baths work, and if there is any evidence of harm.
The authors included 17 small trials involving 366 people in their review. Participants were asked to get into a bath or container of cold water after exercising (i.e., running, cycling or resistance training). In most trials, participants spent 5 to 24 minutes in water that was between 10ºC and 15ºC, although in some cases lower temperatures were used or participants were asked to get in and out of the water at set times. In the studies that compared cold water immersion to resting or no intervention, there was a significant reduction in soreness 1 to 4 days after exercise.
Only few studies, however, compared cold water immersion to other kind of intervention.
"We found some evidence that immersing yourself in cold water after exercise can reduce muscle soreness, but only compared to resting or doing nothing. Some caution around these results is advisable because the people taking part in the trials would have known which treatment they received, and some of the reported benefits may be due to a placebo response," said the lead author of the study, Chris Bleakley of the Health and Rehabilitation Sciences department at the University of Ulster in Country Antrim, Northern Ireland to Science Daily. "There may be better ways to reduce soreness, such as warm water immersion, light jogging or using compression stockings, but we don't currently have enough data to reach any conclusions about these interventions."
Nevertheless, at this stage no clear guidelines for safe and effective cold water immersion can be established as the range of different exercises, temperatures and timing employed by the different studies is just too wide.
On the bright side, there was also a lack of evidence about any harm that could be caused by ice cold baths. In fact, almost none of the studies scrutinized reported any ill effects.
The authors said that higher quality studies are necessary in this respect.
"It is important to consider that cold water immersion induces a degree of shock on the body," said Bleakley. "We need to be sure that people aren't doing anything harmful, especially if they are exposing themselves to very cold water for long periods."
This last statement made by the author of the study is crucial: ice cold baths are not a pleasant thing to do and they do bring a shock to the body. I would not recommend anyone doing them at home without the supervision of someone qualified.
I used to do them while training for the Ironman (and also after the race), and I call tell you from my experience, that they’re not enjoyable thing to do (but, they did helped me with recovery).
The Iron You