From the Guidelines
Cold water immersion has been shown to have numerous physiological effects and benefits on the human body, including improved circulation, reduced inflammation, and enhanced recovery after intense exercise, as supported by recent guidelines from the American Heart Association 1. The benefits of cold water immersion are multifaceted, and research has demonstrated its effectiveness in various contexts. For instance, in the treatment of exertional heatstroke, full-body ice water immersion is considered the most effective immediate treatment, with fatality rates close to zero if the body temperature is brought to less than 40.0°C within 30 min after collapse 1. Some of the key benefits of cold water immersion include:
- Improved circulation due to vasoconstriction followed by vasodilation
- Reduced inflammation and muscle soreness after intense exercise
- Enhanced immune function through increased white blood cell count
- Activation of brown fat, potentially aiding in calorie burning and metabolic health
- Improved mood and reduced stress due to the release of endorphins and norepinephrine
- Potential improvement in sleep quality and increased alertness It is essential to practice cold water immersion safely, starting with brief exposures and gradually building tolerance, and always having someone nearby during the first attempts. Individuals with heart conditions, high blood pressure, or Raynaud's disease should consult a doctor before trying cold plunges. The most recent guidelines from the American Heart Association recommend whole-body cool- to cold-water immersion for 15 minutes or until neurological symptoms resolve for adults and children with heatstroke 1. Overall, the physiological effects and benefits of cold water immersion make it a valuable tool for improving overall health and well-being, and its use is supported by recent and high-quality evidence 1.
From the Research
Physiological Effects of Cold Water Immersion
- Cold water immersion (CWI) has been shown to have various physiological effects on the human body, including an acute inflammatory response, with significant increases in inflammation immediately and 1 hour post-CWI 2.
- CWI has also been found to reduce stress, with a significant reduction in stress observed 12 hours post-CWI 2.
- The immune system is also affected by CWI, with some studies suggesting that repeated cold water immersions can activate the immune system to a slight extent, increasing the proportions of certain immune cells and plasma proteins 3.
- Additionally, CWI has been found to improve sleep quality and quality of life, although the evidence is still limited and more research is needed to fully understand its effects 2, 4.
Benefits of Cold Water Immersion
- CWI has been suggested to have various benefits, including improved mental wellbeing, reduced fatigue, and improved mood, although more research is needed to confirm these findings 2, 4.
- CWI has also been found to have anti-inflammatory effects, which may be beneficial for individuals with inflammation-related conditions 5.
- Furthermore, CWI has been suggested to improve immune function, with some studies finding that habitual cold-water swimmers have fewer and milder infections 6.
- Regular participation in CWI has also been found to improve sleep and well-being in patients with depression, making it a potential add-on treatment for depression 4.
Time-Dependent Effects of Cold Water Immersion
- The effects of CWI have been found to be time-dependent, with different effects observed at different times post-exposure 2.
- For example, CWI has been found to have an acute inflammatory response immediately and 1 hour post-exposure, while stress reduction is observed 12 hours post-exposure 2.
- The time-dependent effects of CWI highlight the need for further research to fully understand its physiological effects and benefits.