So you just saw Chris Hemsworth in an ice filled tub or heard from a friend that swimming at 4 am down at Cottesloe is great for your “brown” fats? Or maybe you’ve been considering cold showers or baths after exercise like all the athletes do but just saw some news suggesting it’s overrated? Have you wondered what the effects are of this pastime and if it is worth doing to assist in giving you all the benefits of exercise or help you train more often with less soreness? Here’s an impartial review of the current science on cold water immersion’s effects on exercise recovery so you can decide if it is worth the hype and your precious time.

Cold or ice water immersion typically involves 5 to 20 min of continuous or split-up immersion in cooled water (~8–15°C) below the shoulders or waist. Since publications by Clarke in 1963, exercise scientists have questioned the use of cold-water immersion. Although popularly perceived as a recovery option to alleviate symptoms of soreness by reducing an “excessive” inflammatory response to exercise, recently, perhaps erroneously, it has become popular to say cold water immersion is detrimental to exercise adaptation.

Some amount of inflammation and blood flow after exercise is helpful for positive adaptation to exercise. Inflammation is a signal for change and if we remove or reduce this complex chemical signal and accompanying transport of recovery substances through blood flow, we could delay adaptations (Malm et al. 2001). So, in the hope to reduce soreness, it has been claimed that we might be reducing beneficial physical or metabolic changes we hope to create with exercise when using cold water immersion. A review of the current state of knowledge as summarised below, indicates a strong opinion either way is not yet evidence based.

Cold water immersion has been shown to impair (Cheng et al. 2017; Yamane et al., 2006), have no effect (Howatson et al., 2009; Halson et al., 2014; Gregson et al., 2013) or have small positive effect on exercise adaptation and recovery (Montgomery et al., 2008; Ihsan et al., 2021; Poppendieck et al. 2013). The Cheng study, which is commonly referenced, showed a negative effect in rat studies after 120 minutes of cooling. Another study by Yamane et al. (2006) is referenced but involved 20 minutes of ice wrapping on rat limbs. These studies are important and indicate need for further research, but are not realistic for how most people use cold baths, so it is concerning that they might be driving strongly negative views or fear mongering on the topic. There also seems to be evidence for mixed effects of cold immersion post aerobic or resistance/strength training. Within resistance training for example, cold water immersion post isolation or compound exercises is reported to have mixed effects in different studies. This makes recommendation difficult for athletes or the general population who often complete both exercise types concurrently. See Ihsan et al. (2021), Malta et al. (2021) and Petersen et al. (2021) for excellent open access reviews on this topic.

If and why something works is important to understand prior to giving strong recommendations. After all, icing improves pain and cold tolerance, which might give the illusion that recovery has improved (Angelopoulos et al., 2022). An important pair of concepts used in biomedical research that help to dissect how a treatment works, are those of placebo and nocebo effects. A placebo is a substitute treatment with no known physiological effect. If a placebo has a positive effect, then the study indicates it is belief (also called bias) that the treatment will work that is causing the effect. Admittedly, it is difficult to use a placebo form of water immersion to remove bias from the potential effects of cold-water immersion, but it has been attempted and the research outcome showed neither positive nor negative effects of cold-water immersion (Wilson et al., 2021). We have to be careful about creating a nocebo effect as well.  This is the case when the statement that a treatment has a “negative effect” actually results in a more negative effect perceived by those who heard that statement and undertook the treatment, than those who had not. The placebo or nocebic effect could strongly affect the impact of cold-water immersion or many other recovery choices (Broatch et al., 2014). Ihsan et al., 2021 for example, provide emerging data challenging the negative effects post resistance training.

Aspetar, a large sports institute in Qatar released results from a survey of coaches and trainers working in over 18 sports. Most common water temperature was in the range of 10 to 15°C, while the most popular duration of immersion was 5 to 10 minutes. Some respondents encouraged use only if the athlete perceives benefit (assisting a placebo effect). Research authors continue to encourage further study as there is variability in time submerged, depth of submersion and temperature throughout the research topic. The effectiveness of any exercise program relies on multiple training (sets, reps, relative intensity) and participant characteristics (gender, age, nutrition and mental stress) which should be considered when interpreting cold water immersion research. Was cold water immersion detrimental or was the context surrounding the exercise program suboptimal for the participants?

To conclude, we could encourage using cold baths for duration less than 10 min, but you should not stress that you are missing any substantial recovery effect, especially if you don’t enjoy cold water immersion. If you want to be extra cautious, don’t cold bath immediately post resistance training, as no studies have shown significant benefit for this exercise modality. This advice will change when the totality of the science indicates differently. Future articles might look at other recovery strategies, contrast bathing (combining cold and hot water immersions) or the psychological or other health benefits that are overconfidently proposed by your local icy Instagram guru. But right now, evidence outside of exercise recovery is minimal. Our conclusion is, save your nice iced out garbage bins for a hot Aussie summer day or a charity challenge.

Written by Tom Murphey, DPT.

“Unfortunately for the wider community scaremongering is easy to present but hard to heal. Research is often messy, and strong stances or beliefs can be both erroneous and dishonest. Here’s an honest review of some high-quality research to provide informed insight so you can make up your own mind.”

For more information not referenced.

·        Tavares, F., Walker, O., Healey, P., Smith, T. B., & Driller, M. (2018). Practical applications of water immersion recovery modalities for team sports. Strength & Conditioning Journal, 40(4), 48-60.

·        Versey NG, Halson SL, Dawson BT. Water immersion recovery for athletes: effect on exercise performance and practical recommendations. Sports Med 2013; 43:1101-1130.

References

·        Aspetar Article – https://www.aspetar.com/journal/upload/PDF/201541916739.pdf

·        Angelopoulos, P., Diakoronas, A., Panagiotopoulos, D., Tsekoura, M., Xaplanteri, P., Koumoundourou, D., … & Fousekis, K. (2022, December). Cold-Water Immersion and Sports Massage Can Improve Pain Sensation but Not Functionality in Athletes with Delayed Onset Muscle Soreness. In Healthcare (Vol. 10, No. 12, p. 2449).

·        Broatch JR, Petersen A, Bishop DJ. Postexercise cold-water immersion benefits are not greater than the placebo effect. Med Sci Sports Exerc 2014; 46:2139- 2147

·        Cheng AJ, Willis SJ, Zinner C, et al. Post‐exercise recovery of contractile function and endurance in humans and mice is accelerated by heating and slowed by cooling skeletal muscle. J Physiol. 2017;595(24):7413–7426.

·        Clarke DH. Effects of immersion in hot and cold water upon recovery of muscular strength following fatiguing isometric exercise. Arch Phys Med Rehabil 1963; 44:565-568.

·        Gregson W, Allan R, Holden S, et al. Postexercise cold-water immersion does not attenuate muscle glycogen resynthesis. Med Sci Sports Exerc. 2013;45(6):1174–1181.

·        Halson SL, Bartram J, West N, Stephens J, Argus CK, Driller MW, et al. Does hydrotherapy help or hinder adaptation to training in competitive cyclists? Med Sci Sports Exerc 2014; 46:1631-1639.

·        Howatson, G., Goodall, S., & Van Someren, K. A. (2009). The influence of cold water immersions on adaptation following a single bout of damaging exercise. European journal of applied physiology, 105, 615-621.

·        Ihsan M, Watson G, Abbiss CR. What are the physiological mechanisms for post-exercise cold water immersion in the recovery from prolonged endurance and intermittent exercise? Sports Med. 2016;46(8):1095–1109.

·        Ihsan, M., Abbiss, C. R., & Allan, R. (2021). Adaptations to post-exercise cold water immersion: friend, foe, or futile?. Frontiers in Sports and Active Living, 3, 714148.

·        Malm C. Exercise-induced muscle damage and inflammation: fact or fiction? Acta Physiol Scand. 2001 Mar;171(3):233-9. doi: 10.1046/j.1365-201x.2001.00825.x. PMID: 11412135.

·        Malta, E. S., Dutra, Y. M., Broatch, J. R., Bishop, D. J., and Zagatto, A. M. (2021). The effects of regular cold-water immersion use on training-induced changes in strength and endurance performance: a systematic review with meta-analysis. Sports Med. 51, 161–174. doi: 10.1007/s40279-020-01362-0

·        Montgomery PG, Pyne DB, Hopkins WG, Dorman JC, Cook K, Minahan CL (2008) Muscle damage, inXammation, and recovery interventions during a 3-day basketball tournament. Eur J Sport Sci 8:241–250

·        Poppendieck, W., Faude, O., Wegmann, M., and Meyer, T. (2013). Cooling and performance recovery of trained athletes: a meta-analytical review. Int. J. Sports Physiol. Perform. 8, 227–242. doi: 10.1123/ijspp.8.3.227

·        Takagi R, Fujita N, Arakawa T, Kawada S, Ishii N, Miki A. Influence of icing on muscle regeneration after crush injury to skeletal muscles in rats. J App Physiol 2011; 110:382-388

·        Wilson LJ, Dimitriou L, Hills FA, Gondek MB, van Wyk A, Turek V, Rivkin T, Villiere A, Jarvis P, Miller S, Turner A, Cockburn E. Cold Water Immersion Offers No Functional or Perceptual Benefit Compared to a Sham Intervention During a Resistance Training Program. J Strength Cond Res. 2021 Oct 1;35(10):2720-2727. doi: 10.1519/JSC.0000000000004097. PMID: 34324460.

·        Yamane M, Teruya H, Nakano M, Ogai R, Ohnishi N, Kosaka M (2006) Post-exercise leg and forearm Xexor muscle cooling in hu mans attenuates endurance training and resistance training eVects on muscle performance and on circulatory adaptation. Eur J Appl Physiol 96:572–580. doi:10.1007/s00421-005-0095-3