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Ice Baths: The Cold Truth About That Morning Plunge

The latest research on cold-water immersion reveals a complex picture of benefits and risks, challenging some popular claims while validating others. A comprehensive study by the University of South Australia, analyzing data from 11 studies with over 3,000 participants, shows that ice baths and cold showers may help with stress and sleep but could temporarily increase inflammation.

“Cold-water immersion has been extensively researched and used in sporting contexts to help athletes recover, but despite its growing popularity among health and wellbeing circles, little is known about its effects on the general population,” explains UniSA researcher Tara Cain.

The study comes at a crucial time, as ice bath sales have skyrocketed from less than 1,000 units to over 90,000 in just one year on Amazon, reflecting a surge in consumer interest despite limited scientific understanding of their effects.

The research focused on immersion in water between 10-15 degrees Celsius (50-59°F), either through ice baths or cold showers. One of the most significant findings was a marked reduction in stress levels 12 hours after exposure, though these benefits didn’t appear immediately.

Perhaps most surprisingly, researchers found that cold exposure initially increases inflammation in the body. “At first glance this seems contradictory, as we know that ice baths are regularly used by elite athletes to reduce inflammation and muscle soreness after exercise,” notes Dr. Ben Singh from UniSA. He explains that “The immediate spike in inflammation is the body’s reaction to the cold as a stressor. It helps the body adapt and recover and is similar to how exercise causes muscle damage before making muscles stronger.”

The study revealed some promising practical benefits. Participants who took regular cold showers experienced a 29% reduction in sick days from work. Additionally, those taking brief cold showers reported slightly higher quality of life scores, though these improvements faded after three months.

Sleep quality also showed improvement among participants using cold-water immersion, though this finding was limited to male subjects, highlighting a significant gap in research – most studies have focused exclusively on men, leaving questions about how women might respond differently to cold exposure.

“Whether you are an elite athlete or everyday wellness seeker – it’s important to understand the effects of what you put your body through,” Cain emphasizes. She notes that current evidence doesn’t clearly indicate who might benefit most or what the ideal approach to cold-water immersion might be.

For those considering adding cold plunges to their wellness routine, researchers advise caution, particularly for individuals with pre-existing health conditions. “People with pre-existing health conditions should take extra care if participating in cold-water immersion experiences as the initial inflammation could have detrimental health impacts,” warns Dr. Singh.

The research team emphasizes that more long-term studies are needed, particularly among diverse populations, to fully understand the lasting effects and practical applications of this increasingly popular wellness practice. While the current evidence suggests potential benefits for stress management and general wellbeing, the highly time-dependent nature of these effects indicates that timing and proper protocol may be crucial for achieving desired results.

The findings were published in PLOS ONE on January 29, 2025, as part of a systematic review and meta-analysis funded by the Medical Research Future Fund.


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