Ice Baths, do they work?
A fast recovery from an injury is vital to the athlete and equally, a fast recovery from an intense training programme is just as important.
For many years, Cryotherapy and cold water immersion (the use of ice and ice baths) has been used in the management of acute sports trauma as an initial treatment. Some authors (Wilcock et al 2006) suggest that cold water immersion (CWI) is the most frequently used treatment for professional sports people, even though controversy remains over its effectiveness.
Research suggests that Cold Water Immersion (CWI) helps to reduce the initial bleeding and oedema/inflammation following the initial injury to cells (Goodall & Howatson 2008). Further research also suggests it helps reduce acute pain and also helps improve muscle functionality quicker.
Physiologically, CWI is thought to cause vasoconstriction to the capillaries 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.
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, is slowed down. Prostaglandin E2 which is also released during injury to heighten pain sensation is further slowed and hence can reduce the pain sensation felt. (Sellwood et al 2007).
Even though CWI is widely used in the management of muscle trauma, debate remains over the validity of the research with most studies having methodical flaws and limitations such as small sample sizes, inadequate blinding and variable and inconsistence standardisation of procedures.
So What is the Latest Evidence?
Cryotherapy has longed been used in the treatment of musculoskeletal disorders with the expectation of reducing tissue temperature which constricts blood vessels and hence reduces swelling and inflammation of damaged tissues. A randomized clinical trial involving 40 participants was undertaken looking at how cryotherapy/CWI can reduce swelling. Participants with swollen limbs were exposed to low temperatures using CWI at three, one-minute immersions. They measured the swelling after 24, 48 and 72hrs thereafter. They found that compared to the control group, there was no significant difference in the swelling of those limbs exposed to CWI. They concluded that CWI is ineffective in reducing swelling in their participants. (Sellwood 2007).
Even though this may be a significant find, debate remains on the validity of the study. Three one minute immersions may not have been long enough to show a significant effect on reducing swelling. Similarly, they 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 that were subjected to intense exercise rather than use subjects with genuine pathologies, low subject numbers and inaccuracies in the standardisation of the procedure.
A study by Goodall & Howatson (2008) concluded similar results however. They used 18 participants in a randomised clinical trial. They used maximal voluntary contraction, Creatine kinase 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, they found no significant difference in any of the markers and concluded CWI does not enhance recovery of damaged tissues. This study lacked a control group, was not blinded, only used males, used low subject numbers and lacked external validity. Once again, the conclusions may not be valid due to the nature in which the studies were conducted.
Other authors agree that cold has limited effects. A more recent study (Peiffer et al 2009) compared 5, 10 and 20min cold water immersion measuring rectal temperature and muscle temperature. 12 Cyclists were exercised to exhaustion and then placed in cold water baths measuring temperature changes at regular intervals. They suggested a cooling effect would provide a positive outcome that CWI is effective. In this study, they found CWI did not affect muscle temperature but did affect rectal temperature. Unfortunately, they were unable to explain why this happened by acknowledged flaws within their procedures and protocols.
However, not authors agree that CWI is ineffective. A recent study (Ingram et al 2009) was conducted on 11 athletes comparing contrast bathing (hot and cold therapies), CWI (Cold water immersion/baths) and a control (no treatment). Here, the authors did blood tests and measured muscle soreness 24hrs and 48hrs before and after exhaustive exercise. A subjective Self-rating Likert scale 0-10 was used to monitor muscle soreness, and creatine kinase (CK) was used from the blood sample to measure the inflammatory response pre and post-exercise.
They found CWI significantly reduced muscle soreness in their athletes, returning them to training quicker than the control group. They also found the contrast group significantly lowered muscle soreness in the first 24hrs 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 simply lacks validity. However, this study did highlight that recovery could be subjective rather than objective, and could provide evidence that placebo may make a contribution.
In a separate study (Morton 2007) compared contrast bathing to CWI. 11 participants were subjected to exhaustive exercise with pre and post plasma lactate levels measured to determine rate of recovery. The study concluded that plasma lactate levels significantly reduce following CWI. Sadly, once again the study had very low subject numbers and had no control group and was not randomised.
Even though CWI remains controversial, other applications may be used to help reduce inflammation and swelling post-injury/cell damage. These include stretching, compression, elevation, massage, non-steroidal anti-inflammatory drugs, steroids, and ultrasound. Low-level laser and some forms of electrotherapy and of course, rest and prescribed exercises. (Sellwood et al 2007).
Cold therapy is still one of the most utilised treatments used 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.
However, because of the low and insignificant side effects that ice therapy can present, ice therapy is still a viable treatment to use in combination with other therapies already discussed.
The other factor of course, is the placebo effect and the mere fact that cold therapy is so well documented, notwithstanding the poor evidence, combined with the explanation that therapists give to why it works, and the simple adage that something is being done, there remains a limited downside to its application. Clearly, however, more quality studies are required to clinically justify its single application in healing speed recovery.
Goodall S, Howatson G (2008) The effect of multiple cold water immersions on indices of muscle damage, Journal of sports science and medicine, 7, 235-280
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
Morton H (2007) Contrast water immersion and plasma lactate levels, Journal of science and medicine in sport, 10, 234
Peiffer J, Abbis C, Watson G (2009) Effect of cold water immersion on body temperature, Journal of sports science, 27, 10
Sellwood K, Brunker P, Williams D, (2007) Ice water immersion and DOMS, a randomized clinical trial, British Journal of Sports Medicine, 41, 297