Ice plunges: Benefits for your body and mind

Cold-water plunges can reduce pain, strengthen your immune system, and improve focus. Here’s how they work – and whether they’re right for you.

Social media is flooded with posts touting the many advantages of ice water immersion. Celebrities, athletes, and other fans of cold-water plunges claim they do it to ease sore muscles, sharpen their focus, and boost their overall health. But is dipping into freezing water really good for you, or can it do more harm than good?

Reduced pain and swelling

“Cold water therapy is the practice of using water at about 15°C to stimulate health benefits and reduce swelling,” explains Dr Daphne Dürr, a GP affiliated with Mediclinic Hermanus. “Applying ice to an injury is a well-known first-aid treatment for soft tissue injuries. This is because ice makes your blood vessels constrict, which can help reduce swelling and inflammation.

“Ice baths, brisk showers or outdoor swims in freezing water will do the same. When you get out of an ice bath, a freezing shower, or an outdoor swim in cold water, your blood vessels expand and pump the oxygen- and nutrient-rich blood back to your muscles. This process can reduce inflammation, pain and stiffness.”

Research from the Sports Science Institute of South Africa (1) suggests that ice baths of 10-15°C can reduce post-exercise inflammation by constricting blood vessels and decreasing metabolic activity. “Many athletes view cold-water immersion as a good recovery strategy after a run or match,” says Dr Dürr. “But if you have to push through pain during exercise, there may be an underlying injury. Don’t cover up that pain with cold as you may delay appropriate healing.”

Immune system boost

Regular cold-water exposure is also said to increase white blood cell counts and improve immune response. A recent Cape Town study (2) found that open-water swimmers experienced almost a third fewer upper-respiratory infections compared to non-swimmers over a winter season.

In the Netherlands, researchers (3) assigned more than 3 000 office workers different morning routines. The control group made no changes to their morning routines, while other groups added a 30, 60, or 90-second blast of cold water to the end of their morning shower. After 60 days, the workers who took cold showers had taken 30% fewer sick days and reported increased energy levels.

These results suggest regular exposure to cold water can potentially stimulate the production of white blood cells and antioxidants, which fight off infections and illnesses. “However, more research is needed to fully understand the relationship between cold water swimming and immune function,” says Dr Dürr.

Improved mental clarity

Taking a dip in cold water is believed to trigger the release of chemicals in your brain, like adrenaline and dopamine, which helps lift your mood, lower stress, and sharpen your focus. The shock of the cold water causes your body to release adrenaline and noradrenaline, giving you a burst of energy and alertness.

Cold water plunges also activate the vagus nerve, which runs from your brain to your gut and plays an important role in helping your body to relax and recover. Your sympathetic nervous system kicks in during stress or danger and triggers the “fight or flight” response, while your parasympathetic nervous system helps your body relax, recover, and function normally when you’re at rest.

Cold water submersion can help slow your heart rate and breathing, helping you feel calmer and less stressed, in turn leading to better mental clarity and focus.

Is cold-water immersion safe for everyone?

“If you have risk factors associated with cardiovascular disease, such as high blood pressure, check with your doctor if it’s safe for you to give cold-water immersion a try,” Dr Dürr advises. “Also, people with heart conditions may take medications like beta blockers, which lower your blood pressure and reduce your heart rate. This could make it harder for your body to adapt to the shock of a sudden temperature drop.”

Cold water dips can be beneficial for many people, but if you’re not sure it's right for you, always seek medical advice first.

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