The use of cold water as a treatment for pain and inflammation can be extensively traced throughout history for thousands of years. Today, cryotherapy is used by many of us in our day-to-day lives without a second thought to its origin or an appreciation as to why we do it - the simple act of applying a cold compress to the bumped head of a child or an ice pack utilized for an achy back or knee, for example.
But, can swimming in cold water or taking a plunge in an ice bath achieve the same results as localised cold application, and is the rising popularity in cold water immersion practices, and the claim that these activities provide a means to manage injury, recovery, and ongoing pain, a viable one?
There are some great cold water plunge tubs on the market if getting to open water is a challenge.
Inflammation in the human body is a protective response involving the activation of the immune system. When suffering from an injury or a virus, the immune system sends crucial pro-inflammation cells, such as macrophages, neutrophils, and eosinophils, to heal the damaged tissue and to protect the body from pathogenic bacteria.
During cold water exposure, vasoconstriction is caused as part of the body’s autonomic survival response, triggered by the dive reflex. This constriction of blood flow is perceived by many to have a potential inhibitory effect on the natural inflammatory process by hindering the movement of healing white blood cells on their essential journey to repair and protect.
In 2017, Peake et al investigated the effects of cold water immersion compared with active recovery in a controlled trial of a group of physically active young men. The aim was to study the impact on inflammation and cell stress responses in skeletal muscle to deduce which would give the better healing responses.
All the men were required to strength train for approximately 45 minutes, twice a week for three months and were then divided into two equal groups to perform different methods of recovery. Group A immersed in a 10c ice bath for ten minutes following exercise and group B rode a stationary bike at a low intensity speed, also for ten minutes.
Muscle mass measurements were taken before and after the trials using MRI and biopsies, and the results showed that, although both groups gained muscle mass and improved strength following training, there were no other substantial associated differences. Thus, challenging the opinion that cold water immersion post-exercise helps to reduce inflammation and aid muscle recovery.
White et al’s study in 2014 had contradictory results, concluding that immersion in 20c and 10c ice baths following exercise aggravated the inflammatory response, potentially leading to negative health outcomes. The study found that engaging in a prolonged duration of cold water immersion may increase the level of cytokines in circulation, which can lead to excess inflammation and autoimmune conditions.
Whilst many professionals and self-appointed cold water gurus will claim that cold water immersion is a miracle cure for a wide variety of conditions, particularly in the world of sport and wellbeing, the fact is, there currently is not enough evidence to prove either way. Recent studies have shown that immersion in cold water has little effect on inflammation and ice baths have not been proven to encourage more pro-inflammatory agents.
However, studies surrounded pain management and long-term relief have been more promising.
Categorized into two main groups, ‘pain’ can be described as chronic - meaning a persistent pain for at least twelve weeks, usually because of injury or an operation, or temporary soreness - which is minor pain due to exercise or over-exertion.
It is widely believed that cold water therapy can benefit both chronic pain and temporary soreness. This may be due to several reasons, including shock induced pain perception alteration, increased mobility and activity, and boosted blood circulation following vasoconstriction caused by the dive reflex.
Make sure you follow safety guidelines before entering a body of cold or freezing water - see our facts regarding staying safe for more details.
Mole et al investigated the effects of cold water swimming on postoperative neuropathic pain during a study in 2018. The subject, a 28-year-old male former triathlete, had developed chronic pain after endoscopic thoracic sympathectomy, a surgical procedure involving the cutting of the sympathetic nerves that control the sweat glands and used to treat excessive sweating and facial flushing.
Standard post-operative procedures failed to alleviate the subject’s pain, and in a desperate need to find relief, he decided to ‘distract’ himself by jumping from a cliff into deep, very cold, open water. He swam around for a minute before finding an exit point, after which he experienced ‘immediate, complete, and sustained remission’ and went on to live his life relatively pain free.
The subject gave this report to the British Medical Journal:
“I initially thought ‘damn this is so cold I’m going to die!’ and I just swam for my life.” However, “Once I was in the water, I had tunnel vision – for the first time in months, I completely forgot about the pain or the fear of shooting pains in my chest if I moved.
“My entire body tingled with the cold. I just knew if I didn’t keep swimming, I’d soon freeze. After a few moments I actually enjoyed it – it was just an immersive rush of adrenaline.
“When I came out of the water, I realised the neuropathic pain had gone away. I couldn’t believe it.”
The exact reasons why the subject became free from pain remain unclear, and the study by Mole et al doesn’t offer a complete explanation, but researchers agree that the cold water swim was most likely responsible. This may be due to several suggestions:
- The sudden shock of the cold water and the genuine fear of drowning may have altered his pain perception, together with the possible production of distraction stimuli which effectively blocked all thoughts except survival, allowing him to momentarily forget about his pain. The shock effectively acted as a ‘reset’.
- The necessity of swimming to safety may have forced him out of his post-operative inactivity.
- The pain relief he felt in the water may have enabled him to move more freely, thus breaking the cycle.
What we can take from this study, is that cold water immersion may be a genuine way to help people manage chronic pain, particularly when a movement such as swimming is also involved. It is worth noting, however, that this type of treatment may not suit all sufferers of chronic pain and each case should be considered individually. It is also important to note that some forms of chronic pain, such as complex regional pain syndrome (CRPS) do not respond to cold water immersion and are in fact made worse by the application.
As with inflammation, cold water immersion studies as a treatment for pain are also inconclusive but show promising results regarding the treatment of muscle recovery after exercise or strenuous activity. During a workout, microtears and microscopic traumas are created in our muscles as part of the natural growth and renewal cycle. This process creates temporary soreness, or delayed onset muscle soreness (DOMS), which is commonly alleviated through active recovery, massage, and in some cases, cold water immersion.
The effects of cold water immersion vs passive recovery on muscle soreness were explored by Fonseca et al during a study of eight highly trained male athletes in 2016. The subjects were required to perform a high intensity workout, which followed with four being immersed in a 5c ice bath for 19 minutes, and the remaining four to recover passively by simply resting.
Readings were taken before and after the trial and showed a preference towards cold water therapy as a post-exercise treatment due to the lower levels of lactate dehydrogenase and other significant markers, indicating that less tissue damage was present compared to the subjects who recovered through rest only. It was noted that perceived soreness and recovery, together with the improvement in muscle power, all tilted in favour of cold water treatment.
Advocates of cold water therapy range far and wide today, from sports experts and personalities, to wellbeing practitioners, and radio and TV hosts. Almost all of them have a personal experience or journey to share, and whilst many will agree that cold water immersion is unlikely to reduce inflammation, many will testify that participating in the activity makes them feel less sore after exercise or adds to their overall feelings of good health. From my personal viewpoint, although cold water swimming cannot potentially be proven to have reduced the inflammation regarding my back injury, my associated chronic pain and soreness has been improved, together with my mobility and my overall feelings of wellbeing. Although studies show that further evaluation is needed regarding cold water immersion as a viable form of treatment regarding both inflammation and pain, I agree with many that in some situations one cannot be treated without an impact upon the other. Inflammation generally involves pain in some form, and by treating the pain through cold water therapy, there will be an undeniable effect on the inflammation, bolstering the discussion that the application of the treatment should also very much be viewed on a case-by-case basis.
Don't forget to have fun too - cold water swimming isn't just about pain management!