“So What’s Really the Deal with Cold Therapy (Cryotherapy)?”

By: O2X Injury Prevention Specialist Nicholas Schumacher, DPT

As a physical therapist, I get asked often:

• “Should I ice my ankle sprain?”
• “Do ice baths help with recovery?”
• “Should I take cold showers?

So what really does the research say about these modalities?

Should I Ice an Acute Injury?

When applied to the skin, ice (and other forms of cryotherapy) reduces nerve conduction, reduces the production of inflammatory chemicals (which create aching pain post-injury), and inhibits pain transmission up the spinal cord. As a result, the overall intensity perceived by the brain is reduced. Given that NSAIDs (Aleve, Advil, etc.) have been shown to reduce/slow the healing of soft tissues and increase the risk of stomach ulcers and heart complications, ice is no doubt a much better alternative to these drugs!

There is no question that cryotherapy (cold therapy) reduces pain; however, does it improve healing? In 1978, Mirkin & Hoffman proposed the term “RICE” (rest, ice, compression, and elevation) in their book “Sports Medicine.” This concept became deeply rooted in the sports medicine and rehabilitation community for many years. However, in 2019, a more evidence-based model was proposed by Dubois & Esculier with the acronym “PEACE & LOVE” (protection, elevation, avoid anti-inflammatory drugs, compression, and education & loading, optimism, vascularization, and exercise). “PEACE” is recommended for the acute stage of healing (first week), while “LOVE” is recommended for thereafter (subacute and chronic stages of healing).

As you can see, ice is no longer consistently recommended for acute injury management. In a 2017 study, Singh et. al discovered that icing an acute injury could potentially disrupt inflammation and angiogenesis (growth of new vessels), which may lead to impaired tissue healing and redundant collagen synthesis (scar tissue). Such effects could increase future injury risk. Therefore, I rarely ever recommend icing an acute injury. That being said, I do recommend icing in cases where a patient is unable to participate in productive rehabilitation exercises due to high levels of pain and swelling. I would rather they ice than use NSAIDs or miss out on effective rehabilitation exercises.

Should I Use Cold Water Immersion for Recovery?

Cold water immersion (ice baths) is a common modality used by rehabilitation professionals, coaches, and strength coaches; however, is this practice really supported by evidence? It is generally assumed that post-exercise recovery strategies will reduce muscle fatigue and help exercising individuals to maintain the required workload during subsequent training sessions, thereby improving the effects of exercise training while reducing the risk of injury (Barnett, 2006). However, the evidence does not appear to support this.

A randomized, controlled trial in 2017 by Roberts et al. found that, “Cold water immersion 1) substantially attenuated long-term gains in muscle mass and strength, and 2) delated/or suppressed the activity of satellite cells and kinases in the mTOR pathway [the primary muscle-growth pathway] during recovery from strength exercise.” In this study, cold water immersion for 10 minutes following strength training was compared to an active recovery on a bike. It appears that active recovery is our best recovery modality following strength training. The same conclusion can likely be made post-endurance training since similar pathways are required for endurance gains. In addition to active recovery, the intake of high-antioxidant fruits (tart cherry juice, watermelon, pomegranate, and berries) can significantly improve muscle recovery (Kubala, 2021).

Should I Take Cold Showers for Weight Management?

All humans have brown adipose tissue (fat), which can increase with cold exposure. Brown adipose tissue is a thermogenic tissue that produces heat when activated by cold exposure. In a 2013 (van der Lans et al.) study, subjects were exposed to an environmental temperature of 60 degrees for 6 hours per day for 10 consecutive days. After the 10 days, the subjects had a significant increase in brown adipose tissue, but there was no increase in the subjects’ basal metabolisms. Although this study used cool air rather than cold-water exposure, we can likely conclude that daily cold showers will not provide a significant enough stimulus for increased overall metabolism.

That being said, significantly increased metabolisms have been reported in Korean cold-water divers during the winter months compared to the summer months (Kang et at., 1963). During the time this data was collected (1960s), these divers were wearing thin cotton swimsuits while diving in waters with temperatures in the mid-50s. These women were exposed to cold temperatures for hours per week, so this group may not apply to individuals taking short cold showers.

No definitive answer can be provided based on the current research. Therefore, it appears that daily cold showers may not be worth the effort for weight management. That being said, a large study of 3,018 participants in the Netherlands found that 30 days of cold showers for 30-90 s seconds each morning resulted in a 29% reduction in sickness-related work absence at the 90-day follow-up (Buijze, 2016). There was no added benefit of a 90-second shower versus a 30-second shower, so you can opt for the shorter one!

IN SUMMARY

• I recommend that you do not ice your injuries unless needed for pain relief. Ice and other cold therapies do not appear to help with healing whatsoever.
• Cold water immersion seems to slow muscle recovery rather than promote it. Active recovery and high-antioxidant fruits appear to be more effective.
• Morning showers do not provide any definitive improvement in basal metabolism. However, they have been shown to reduce the intensity of sickness from the flu, colds, etc.

Reference List

Lee JY, Park J, Kim S. Cold adaptation, aging, and Korean women divers haenyeo. J Physiol Anthropol. 2017;36(1):33. Published 2017 Aug 8. doi:10.1186/s40101-017-0146-6

Barnett A. Using recovery modalities between training sessions in elite athletes: does it help?. Sports Med. 2006;36(9):781-796. doi:10.2165/00007256-200636090-00005

Buijze GA, Sierevelt IN, van der Heijden BC, Dijkgraaf MG, Frings-Dresen MH. The Effect of Cold Showering on Health and Work: A Randomized Controlled Trial [published correction appears in PLoS One. 2018 Aug 2;13(8):e0201978]. PLoS One. 2016;11(9):e0161749. Published 2016 Sep 15. doi:10.1371/journal.pone.0161749

Dubois B, Esculier JF. Soft-tissue injuries simply need PEACE and LOVE. Br J Sports Med. 2020;54(2):72-73. doi:10.1136/bjsports-2019-101253

Esperland D, de Weerd L, Mercer JB. Health effects of voluntary exposure to cold water – a continuing subject of debate. Int J Circumpolar Health. 2022;81(1):2111789. doi:10.1080/22423982.2022.2111789

van der Lans AA, Hoeks J, Brans B, et al. Cold acclimation recruits human brown fat and increases nonshivering thermogenesis. J Clin Invest. 2013;123(8):3395-3403. doi:10.1172/JCI68993

Roberts LA, Raastad T, Markworth JF, et al. Post-exercise cold water immersion attenuates acute anabolic signalling and long-term adaptations in muscle to strength training. J Physiol. 2015;593(18):4285-4301. doi:10.1113/JP270570

Wang ZR, Ni GX. Is it time to put traditional cold therapy in rehabilitation of soft-tissue injuries out to pasture?. World J Clin Cases. 2021;9(17):4116-4122. doi:10.12998/wjcc.v9.i17.4116