Despite the lack of scientific evidence supporting the use of ice‐water immersion to prevent DOMS in the sporting environment, it remains widely used in clinical practice as a recovery technique.22,33
Although treatment protocols vary with regard to the duration and frequency of immersions and the temporal relationship with exercise, anecdotal evidence suggests that the most commonly used protocol in Australia involves 1 min ice‐water immersion followed by 1 min out of water for a total of three cycles, applied immediately after a bout of exercise. We aimed to test the efficacy of this common clinical protocol. Our double‐blind randomised controlled trial demonstrated that in a group of untrained healthy volunteers, ice‐water immersion produced no significant change in most markers of DOMS. The only exception to this was pain on concentric quadriceps contraction at 24 h, which was actually increased in the intervention group compared with controls, contrary to the hypothesis at the study outset. However, the small magnitude of this difference in pain between groups is of questionable clinical significance.
Serum CK is accepted widely as a marker of muscle damage.11,34,35,36
In the current study, a peak median CK increase of 170% from baseline occurred at 24 h. This suggests that the eccentric exercise protocol used was successful in eliciting muscle damage, although peak increases up to 600% have been reported in other studies with more aggressive eccentric quadriceps loads.2,5,6,37,38
Increases in pain and reductions in quadriceps strength at 24 h in both groups further attest to the success of the exercise protocol in inducing DOMS.
Pain was the only parameter significantly influenced by the treatment in our study, and contrary to expectation, ice‐water immersion actually increased the severity of pain after 24 h of eccentric exercise. It is unclear why pain increased in participants subjected to ice‐water immersion. A noxious cold stimulus such as ice‐water immersion is known to evoke varied sensory experiences in humans including cold, pain, ache and prickling, which are mediated by thermoreceptors and nociceptors.39
Temperatures <15°C are associated with additional perceptions of pain and ache as well as cold, and peak pain sensation occurs at a temperature of approximately 3°C for at least 10 s.39
Application of noxious cold stimulus for >1 min may also stimulate vascular and muscle nociceptors. The ice‐water immersion group in the current study may have therefore experienced a significant painful stimulus at the time of immersion. The experience of pain is determined by both physiological and psychological influences, and the meaning or context that a subject attaches to a particular stimulus can influence the subjective interpretation of the pain they experience.40,41
Thus, the ice‐water immersion group may have had a heightened subjective interpretation of discomfort on performing the sit‐to‐stand activity (which was the first outcome reassessed at 24 h) secondary to both their expectation of being sore as a result of the exercise on the previous day and the significant additional pain experienced during immersion.
Contrary to the research hypothesis, the ice‐water immersion protocol used in the current study did not influence CK levels. It is likely that a bout of immersion immediately after exercise as used in the current study would not have had a sustained effect on vessel permeability and was therefore unlikely to influence CK efflux from the damaged muscle on subsequent days. This may also explain why there was no effect on swelling over subsequent days.
The lack of a treatment effect for other outcomes may be due to the eccentric exercise protocol inducing only low levels of muscle damage. This is reflected by relatively low pain scores, small percentage strength deficits and small CK increases after exercise (tables 4 and 5). In comparison with other studies, which have demonstrated mean VAS scores of up to 71 mm after exercise with 10 sets of 10 maximal hamstring contractions,25
for example, the control group in the current study achieved only a maximum of 27 mm of pain (on isometric contraction at 24 h), and the intervention group a maximum of 38 mm (again on isometric contraction at 24 h). The strength deficits observed in this study were also small compared with other studies of DOMS which demonstrated 25–40% strength reduction at 24 h and increases in mean CK of 278–600% above baseline 2,5,6,30
. Thus, because of the small strength deficits induced, there was limited capacity for the treatment to be effective, which is likely to have contributed to the non‐significant findings.
With all physical activity there is a psychological component that can enhance performance,42
particularly in elite athletes who use many different types of recovery strategies that have little evidence behind them. What may be considered beneficial by one athlete as a recovery technique is not necessarily of any perceived benefit to another. Over time, athletes develop their own rituals of preparation and recovery that they use before and after every competition performance or training bout. The perceived psychological benefit of using a familiar recovery technique may have a greater influence on performance than perhaps the actual physiological benefit of that technique. Although the present study used a control intervention in tepid water to account for these potential placebo effects of ice‐water immersion, the study sample did not include athletes, so it is possible that different results would be obtained in a group of elite athletes.
What is already known on this topic
- Ice‐water immersion is a commonly used treatment in sporting populations, believed to limit the inflammatory response after muscle damage mainly through a vasoconstrictive effect.
- Previous literature evaluating the effect of ice‐water immersion on eccentrically induced muscle damage contains conflicting results involving poorly justified protocols of immersion that are also impractical to apply.
What this study adds
- This study challenges the use of ice‐water immersion in athletes, given that for eccentric exercise‐induced muscle damage, ice‐water immersion offers no benefit for pain, swelling, isometric strength and function, and in fact may make athletes more sore the following day.
The main strength of this study was the use of a rigorous double‐blind randomised control design, which included a control intervention (tepid water bath) to assess the effects of temperature alone with few confounders. Another strength of this study is that it evaluated a clinically feasible treatment regimen that is commonly used in Australia.
Future research may involve repeating the current study with a more damaging eccentric exercise protocol to be able to determine significant differences between treatment and placebo interventions for all outcome measures.
Future research may focus on specific groups of elite athletes who regularly use ice‐water immersion and develop reliable functional measures for each group that may demonstrate more subtle objective deficits resulting from muscle soreness. It would be valuable to assess athletes in their chosen sport to determine the specific muscle symptoms that result from an intense competition performance as it may be possible to identify a reliable model of sports‐induced muscle damage, and reliable outcome measures that are affected by muscle soreness. From this, the effects of various interventions such as ice‐water immersion could be properly assessed in sports‐induced muscle soreness.
In conclusion, this study challenges the use of this intervention as a recovery strategy by athletes given that ice‐water immersion to minimise or prevent symptoms of muscle damage after eccentric exercise is ineffectual in young, relatively untrained individuals. Given that trained athletes are relatively well protected against DOMS, ice‐water immersion is likely to offer them even less benefit for the minimal soreness they may experience after eccentric exercise.