A recent review suggests that while cold plunges may offer short-term benefits, people could be overstating their effectiveness. Ongoing research is delving into the potential health perks of cold-water immersion, such as cold showers or ice baths. An analysis revealed that this practice could potentially reduce sick days, enhance sleep quality and overall well-being, and alleviate stress levels.
Further investigation is required to explore the sustained advantages of cold-water immersion. A recent study published in PLOS One scrutinized eleven research projects to determine the actual health benefits of cold-water immersion, often referred to as cold plunges or cold water therapy. This scrutiny focused on the impact of cold-water immersion on cognitive, psychological, and physiological health.
The review discovered that individuals engaging in cold-water immersion might experience temporary stress relief, reduced absences due to illness, and enhancements in sleep quality and quality of life. The researchers advocate for more studies to scrutinize the long-term effects of cold-water immersion, incorporate diverse populations, investigate various outcomes, and explore the relationship between dosage and response.
What are the optimal temperatures for cold plunges? Cold-water immersion encompasses a wide range of activities involving exposure to cold water. The study authors highlighted its surge in popularity among athletes and the general public. While ideal conditions for optimal cold immersion remain debatable, Performance Psychologist & Lecturer Dylan Colbert, PhD, outlined three key factors. “Firstly, the recommended water temperature is between 10 and 15 degrees Celsius. Secondly, submerging up to neck level is advised to avoid potential health risks associated with dunking the head. Lastly, research suggests an optimal immersion duration of about 12 minutes,” Colbert shared.
The current study defined cold-water immersion as practices like showering, ice baths, or immersing in water at 15 degrees Celsius or lower for at least 30 seconds. The review included studies where water reached chest level or higher and excluded those involving protective clothing. Ten studies focused on bath cold-water immersion, while one examined cold showers.
How does cold-water immersion impact health and well-being? The researchers aimed to comprehend the effects of cold-water immersion better. They scoured ten databases for relevant randomized controlled trials, evaluating methodological rigor based on factors like group comparisons, blinding, and follow-up. The review identified seven moderately and four highly qualitative studies.
The effects of cold-water immersion on sleep quality, stress levels, mood, and immunity were examined. Meta-analyses were conducted where data permitted to determine the overall impact of cold-water immersion on health and well-being.
Several studies examined the effects of cold-water immersion on various outcomes. A narrative synthesis was conducted for outcomes that did not meet meta-analysis criteria. Meta-analyses were performed for inflammation, stress, and immunity. The research included eleven studies with a total of 3,177 participants, mostly male. Highly-trained athletes were excluded from the analysis.
The findings showed that cold-water immersion increased inflammation immediately and one hour post-treatment. Study author Tara Cain explained that this short-term inflammation could lead to long-term benefits by reducing overall inflammation and aiding in recovery. Cold-water immersion was also found to reduce stress 12 hours after exposure, but not immediately or at other time points. Immunity changes were not significant immediately after immersion.
Some additional benefits of cold-water immersion were identified through narrative syntheses, such as a potential reduction in sickness absence and improved quality of life. However, there was no significant difference in illness days between control and intervention groups. Sleep quality was found to improve with cold-water immersion, but the effects were not sustained long-term.
The review had limitations, including a focus on healthy adults and limited representation of women in the studies. Variability in immersion protocols and small sample sizes also impacted the generalizability of the findings. Single immersions and post-exercise immersions were common in the studies, limiting the assessment of long-term effects. The authors advise caution when interpreting results based on outcomes reported by only a single study.
There exists a potential risk for confounding in the trial that examined sleep quality. Likewise, the research on the impacts of cold-water immersion on illness and quality of life relied on self-reported data, introducing a risk of bias. Furthermore, the study encountered challenges with participants’ adherence to cold-water immersion over time. The researchers also observed that the effects of cold-water immersion appeared to be closely related to the duration of exposure, suggesting that further investigation into this aspect would be beneficial. The authors suggested that upcoming studies could explore the safety of cold-water immersion and investigate participants’ experiences.
Are you considering cold-water immersion? The findings emphasize the necessity for more extensive research to explore the long-term consequences and validate the effects on different outcomes. “Currently, the body of high-quality research is insufficient to definitively determine who gains the most benefit from cold-water immersion or the most effective approach to its implementation. Conducting more long-term research involving diverse populations is crucial to comprehending its enduring effects and practical utility,” noted Cain.
David Merrill, MD, PhD, a board-certified geriatric psychiatrist at Providence Saint John’s Health Center in Santa Monica, CA, and Singleton Endowed Chair in Integrative Brain Health, who was not part of the study, highlighted the importance of conducting long-term studies to evaluate the full extent of its impact. “At present, cold plunging appears to offer immediate, short-term advantages. Individuals often report feeling more alert, less anxious, and even euphoric immediately following a plunge, likely due to the release of endorphins and adrenaline,” stated David Merrill, MD, PhD.
“The question at hand is whether these immediate effects translate into long-term enhancements in mood and resilience. We require studies that monitor individuals over an extended period to determine if regular exposure to cold conditions yields enduring mental health benefits, particularly for individuals dealing with clinical depression or anxiety,” he added.
