A fast recovery from injury is vital to athletes, as is a quick recovery from an intense training program. For many years cold water immersion (CWI) – the use of ice and ice baths – have been used in the management of acute sports trauma as an initial treatment.
The use of CWI has often been controversial, with physiologist Jonathan Leeder6 the latest to question its effectiveness, and suggest long-term use of the practice could be detrimental to performance. However, exponents of the treatment include elite athletes Paula Radcliffe and Andy Murray and authors such as Wilcock et al. suggest it is the most frequently used treatment for professional sports people. So, what’s the science behind CWI?
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Research has suggested that CWI helps to reduce the initial bleeding and oedema/inflammation following injury to cells, 1 reduces acute pain and helps improve muscle functionality quicker. Physiologically, CWI is thought to cause a decrease in the diameter of blood cells, which limits the trauma and bleeding of cells. Furthermore, the metabolism of cells also slows down, thereby reducing further inflammation and swelling which can result from the trauma. Reducing swelling and inflammation can increase rate of recovery and help functionality faster.
Other studies have also suggested that chemicals and enzymes released during injury, such as Creatine Kinase (CK), which can lead to delayed onset muscle soreness (DOMS) and muscle wastage, are slowed down. CK, a marker or a byproduct of DOMS, is a useful objective and reliable marker in the diagnosis of DOMS. Prostaglandin E2, which is also released during injury to heighten pain sensation, is further slowed and hence pain can be reduced.2
Even though CWI is widely used in the management of muscle trauma, debate remains over the validity of the research. Most studies have methodical flaws and limitations such as small sample sizes, inadequate blinding and variable and inconsistent standardization of procedures.
What is the Latest Evidence?
A randomized clinical trial involving 40 participants was conducted by Sellwood et al. and published in the British Journal of Sports Medicine. The research looked at the effects of ice water immersion on reducing DOMS after exercise. Participants with swollen limbs were exposed to low temperatures using CWI during three one-minute immersions.
Swelling was then measured after 24, 48 and 72 hours. The study found that, compared to the control group, there was no significant difference in the swelling of those limbs exposed to CWI, and thus concluded that CWI is ineffective in reducing swelling in their participants.2 Even though this may be a significant find, debate remains on the validity of the study.
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Three one-minute immersions may not have been long enough to show a significant effect on reducing swelling. Similarly, the test measured swelling using the girth of the limb, rather than using diagnostic ultrasound, which may have been more accurate. Other flaws were the use of normal participants subjected to intense exercise rather than those with genuine pathologies, low subject numbers and inaccuracies in the standardization of the procedure.
A study by Goodall and Howatson in 20081 resulted in similar findings.
They used 18 participants in a randomized clinical trial. They used maximal voluntary contraction, CK levels in blood samples (to measure inflammation) and range of motion of joints as markers. After exhaustive exercises they subjected the participants to CWI for 12 minutes, found no significant difference in any of the markers and so concluded CWI does not enhance recovery of damaged tissues. However, the conclusions may not be valid due to the nature in which the study was conducted – it lacked a control group, was not blinded, only used males, had low subject numbers and lacked external validity.
However, not all authors agree that CWI is ineffective. A recent study3 was conducted on 11 athletes, comparing contrast bathing (hot and cold therapies), CWI and a control group. Here, the authors did blood tests and measured muscle soreness 24 and 48 hours before and after exhaustive exercise. A subjective self-rating Likert scale where recipients answer a question using a scale of 0-10 was used to monitor muscle soreness, and CK was used from the blood sample to measure the inflammatory response pre- and post-exercise.
The study found CWI significantly reduced muscle soreness in their athletes, returning them to training quicker than the control group.
They also found the contrast group experienced significantly lower muscle soreness in the first 24 hours but didn’t return to sport any faster than the control group. Interestingly, there was no significant difference in the CK levels from the blood samples between the three groups.
Sadly once again, even though these results are more encouraging, with low subject numbers and using subjective tests as the only significant marker to endorse CWI, the study lacks validity. However, it did highlight that recovery can be subjective rather than objective and provide evidence that placebo may make a contribution.
CWI remains a controversial procedure and other applications may be used to help reduce inflammation and swelling post-injury/cell damage. These include stretching, compression, elevation, massage, nonsteroidal anti-inflammatory drugs, steroids, ultrasound, low-level laser and some forms of electrotherapy and, of course, rest and prescribed exercises.
Strength and conditioning coach
Aviva Premiership rugby union side London Wasps
|We have been using ice baths since 2003-2004. At the start it wasn’t very sophisticated; it was just a case of dropping a load of ice bags into a bath. We weren’t really working to any guidelines,” says Crofton. Those days have long since passed. Now Wasps have baths that are electronically controlled between 10 and 15°C. After a game the players stay in the baths for eight to 10 minutes and, when they use them occasionally mid-week, it is for five minutes after training.
Crofton is a firm believer in the effectiveness of the treatment in reducing inflammation in muscles and joints and believes part of the problem is that not enough research – or the right sort – has been commissioned.
“Lots of the research in rugby has been unrealistic and used the wrong environments,” he stresses. “For instance, they use university-level rugby players that don’t play to the same intensity.”
While he admits that, to gauge the effectiveness, he and other coaches are partly reliant on subjective feedback from players, he believes that coaches need to avoid being “one dimensional” in their recovery treatments.
And what do the players think about the method? “We try to be sensitive to players and take a sensible approach – in winter time don’t use it as much if it’s really cold,” he says. “We have a squad of 30-40 really competitive personalities, so of course not all of them are going to want to do it, but most see the benefit in it.”
CWI is still one of the most utilized treatments for acute trauma/injury by sports therapists around the world.
The lack of scientific evidence and the reliability of studies do question its usage and effectiveness. There are plenty of protocols, but such is the variation in the standardization of the applications, it is impossible to recommend an accurate and reliable protocol.
However, because of the low and insignificant side effects that ice therapy can present, this method is still a viable treatment to use in combination with other therapies already discussed. The other factor is the placebo effect; the mere fact that cold therapy is so well documented and the simple fact that something is being done can lead to positive results.
While there is limited downside to its application, it is clear that more high-quality studies are required to clinically justify its single application in speeding up recovery.
- Goodall and Howatson G. (2008). The effect of multiple cold water immersions on indices of muscle damage. Journal of Sports Science and Medicine, 7:235-280.
- Sellwood K, Brunker P, Williams D (2007). Ice water immersion and DOMS, a randomized clinical trial, British Journal of Sports Medicine, 41:297.
- Ingram J, Dawson B, Goodman C (2009). Effect of water immersion methods on post exercise recovery from simulated team sport exercises. Journal of Sport Science and Medicine , 417.
- Leeder’s study will be published later in 2011. For more information visit http://www.eis2win.co.uk/pages/news_ratingrecoveryforeliteathletes.aspx.
Source: Fitpro Network