Ice baths or cold water immersion have been promoted by many coaches as a means to reduce post exercise muscle soreness and inflammation as well as to enhance recovery from hard training or race efforts.
While coaches and athletes are always looking for that special modality to speed recovery and thereby enhance performance, are ice baths proven to offer this benefit?
A 2013 study
published in Medicine & Science in Sports & Exercise investigated the effects of postexercise cold water immersion on tissue oxygenation and blood volume changes after intense exercise. Nine physically active men performed 30 min of continuous running at 70% of their maximal treadmill velocity , followed by 10 bouts of intermittent running at maximal speed. After exercise, one of the participants’ legs was immersed in a cold water bath (50°F) to the level of their gluteal fold for 15 min. The contralateral leg remained outside the water bath and served as a control . Vastus lateralis (lateral thigh muscle) skin temperature, vastus lateralis oxygenation, and blood volume changes (total hemoglobin volume) were monitored continuously throughout exercise using near-infrared spectroscopy. Postexercise cooling was shown to decrease microvascular perfusion and muscle metabolic activity
The authors state that these findings are consistent with the suggested mechanisms by which cold water immersion is hypothesized to improve local muscle recovery. However, this study did not measure the effects of cold water immersion on tissue recovery, muscle soreness or physical performance.
A 2009 study
published in the Journal of Sports Sciences
investigated the effect of water immersion on physical performance tests and self perception of fatigue and recovery during a soccer tournament. Twenty soccer players played four matches in 4 days while undertaking either cold-water immersion (50°F) or neutral temperature water immersion (93°F) after each match. Physical performance tests including: vertical jump height, heart rate, and rating of perceived exertion (a self rating on a 1 to 10 scale on how fatigued they feel) after performing a 5 min run and 12×20 meter sprints were compared while inflammatory markers (hormones that are released into the blood when there is muscle tissue damage) were measured at 90 minutes before each match and 22 hours after the final match. In addition, self perceived measures of recovery (physical, mental, leg soreness, and general fatigue) were recorded 22 hours after each match.
Study results showed that there were no significant reductions in vertical jump height and repeated sprint ability over the 4-day tournament with no differences between groups. Post-shuttle run rating of perceived exertion increased over the tournament in both groups, whereas the perceptions of leg soreness and general fatigue were lower in the cold-water immersion group than the neutral temperature immersion group over the tournament.
This study suggests that while cold water immersion promotes an athletes subjective perception of decreased soreness, perhaps indicating the popularity of its use, there is no proof of enhanced athletic performance.
Similarly, a 2007 study
presented in the Journal of Sports Sciences showed that soaking in 50°F water after a 90-min intermittent shuttle run resulted in severe muscle soreness, temporary muscular dysfunction, and elevated hormonal markers of muscle damage, all peaking within 48 hours after exercise. Cold water immersion administered immediately after exercise reduced muscle soreness at 1, 24, and 48 hours after exercise but had no effect on the creatine kinase response.
This study also indicated that the athletes perception of soreness was reduced, but there was no change in the volume or presence markers of inflammation thus indicating that ice immersion did not impact tissue recovery.
The above findings were corroborated in 2010 by a database review
of 17 randomized trials published in the comparing the effect of using cold-water immersion after exercise with: passive intervention (rest/no intervention), contrast immersion, warm-water immersion, active recovery, compression, or a different duration/dosage of cold-water immersion. Primary outcomes were muscle soreness or tenderness pain on palpation, and subjective recovery (return to previous activities without signs or symptoms).
Results indicated that there was some evidence that cold-water immersion reduces delayed onset muscle soreness after exercise compared with passive interventions involving rest or no intervention.
Similarly, 10 studies were included in a systematic review and metanalysis of 35 articles, as presented in Physical Therapy in Sport in 2012, that analyzed the effects of cryotherapy, while the remaining studied the effect of massage, stretching and the effects of low-intensity exercise in the management of delayed onset muscle soreness. This analysis stated that there was inconclusive evidence to support the use of cryotherapy on the recovery of muscle soreness
A report presented in 2014 in the Journal Medicine & Science in Sports & Exercise
studied thirty males as they performed a high-intensity interval training session, comprised of 4 × 30 second sprints, immediately followed by one of the following three 15-minute recovery conditions: cold water immersion (50°F ), thermoneutral water immersion placebo (95°F ), or thermoneutral water immersion control (95°F). An intramuscular thermistor was inserted during exercise and recovery to record muscle temperature. Swelling (thigh girth), pain threshold/tolerance, interleukin 6 concentration, and total leukocyte, neutrophil, and lymphocyte counts were recorded at baseline, postexercise, postrecovery, and 1, 24, and 48 hours postexercise. Testing consisted of a maximal voluntary isometric contraction of the quadriceps (thigh muscle) performed at the same time points, with the exception of postexercise. Self-assessments of readiness for exercise, fatigue, vigor, sleepiness, pain, and belief of recovery effectiveness were also completed.
Results indicated that leg strength after the quadricep isometric contraction and ratings of readiness for exercise, pain, and vigor were significantly impaired in the thermoneutral control group as compared with those in the cold water immersion and thermoneutral placebo groups which were similar to each other. These results indicate that a recovery placebo administered after a high-intensity interval training session is superior in the recovery of muscle strength over 48 hours as compared to warm water immersion and is as effective as cold water immersion. These results suggest that the commonly hypothesized physiological benefits surrounding cold water immersion are at least partly placebo related.
In addition to the above findings, a current training theory suggests that fatigue and post exercise tissue inflammation are vital components to promote long-term tissue adaptation to training and ultimate performance improvement. Shona Halson, a researcher at the Australian Institute of Sport states: theory suggests that fatigue and/or inflammation post exercise is necessary to promote long-term adaptations to training and subsequent improvements in performance. The author proposes that cold water immersion may decrease adaptations to training due to minimization of fatigue and inflammation that occurs following training. What Halson suggests, is that while iced immersion may offer short term relief from muscle soreness, in the long run it may reduce training adaptation thus inhibiting fitness development by eliminating or reducing inflammation that signals your body to adapt and get stronger after training.
Halson presented a 2014 study
in which thirty four male endurance-trained competitive cyclists were randomized to cold water immersion for four times per week for 15 min at 59°F or a control (passive recovery) group for 7 days of baseline training followed by 21 days of intensified training, followed by an 11 day taper. Each week, cyclists completed a series of high intensity interval cycling performance tests and a ten-minute time trial. Results were variable with several of the performance measures showing a small benefit for the ice bath group while other results showed no benefit.
The overall conclusion is that the effects of ice bath on performance were “unclear“ but the study also did not find any evidence that the cyclists in the ice bath group not improving as much as the control group. This study does not support recent speculation that cold water immersion is detrimental to performance. However, further research in this area is warranted because one question that this study brings up is whether the study was long enough to affect training adaptations or lack of training adaptation, whichever the result may be
What is the practical application of these research findings? While research results are mixed, current findings suggest the following about ice immersion:
1. Cold water immersion may reduce delayed onset muscle soreness
2. Cold water immersion does not appear to affect the markers of tissue inflammation
3. Cold water immersion does not appear to enhance performance following its application
4. Cold water immersion proposed benefits may be related to a placebo effect
5. Timing and frequency of use of cold water immersion should be taken into consideration as it may impact training adaptations
Summarily, There are still many questions that need asked and answered when it comes to the use of ice immersion. Ultimately, it is the coaches and athletes choice to use ice baths as a recovery modality following hard workouts or race efforts. Currently scientific literature shows evidence that, upon use of cold water immersion or ice baths, soreness resulting from hard efforts may be reduced, but there is not substantial evidence to prove that this treatment modality has an impact upon followup performance. In addition, the choice of when to use this modality may or may not negatively impact training adaptations.