Cold Plunge Science

Cold plunge tubs have become an increasingly popular trend in gyms and homes alike, with some people hailing their practice as transformative. Before jumping in a cold plunge tub or cold-water immersion (CWI), however, it's essential to understand its scientific basis.

An extended exposure could cause hypothermia and frostbite, with any prolongued exposure increasing the risk of heart arrhythmias and shivering. The total time in cold water exposure may vary from person to person and the treatment may not be for everyone. That being said when done correctly there are some amazing benefits including:

1. Increased Blood Circulation

Jumping into frigid waters has quickly become the latest wellness trend endorsed by celebrities, athletes and influencers. Also known as polar bear plunges, cold water immersion has been proven to reduce muscle soreness and aid workout recovery while simultaneously lowering inflammation levels and strengthening immunity.

Submerged in cold water, blood vessels constrict to protect core temperature by diverting blood away from extremities. But as soon as you emerge from this cold environment, they immediately reopen, pumping more blood through and improving long-term circulation - helping your body deliver oxygen and nutrients directly to tissues and cells.

2. Reduced Inflammation

Your blood carries more than oxygen to your tissues; it also contains disease fighting compounds that protect from illness and promote healing. One study discovered that cold plunges were effective at decreasing inflammation associated with exercise-related muscle soreness (DOMS).

Before diving in to cold water, it's essential that you consult your physician. Doing so could put you at risk of hypothermia and uncontrolled hyperventilating; to minimize these risks it's advisable to gradually introduce cold water by starting with feet and legs before slowly increasing exposure over time to arms, torso and face.

3. Increased Endurance

TikTok and Instagram is filled with influencers and fitness trainers guzzling down ice-cold water, touting its benefits for muscle soreness relief and faster workout recovery. Cold immersion has also been proven to reduce inflammation and immune reactions after exercise allowing you to recover faster from workout sessions as well as perform better during subsequent sessions.

Consistent exposure to cold temperature increases brown fat, which helps regulate body temperature while burning calories and improving mental resilience and endurance. If your goal is to build strength and muscle mass, however, cold plunges should only be taken on days other than directly following resistance training sessions.

4. Improved Sleep

Undergoing a cold plunge can help reset your internal circadian rhythm to correspond with your natural sleep cycle and promote relaxation and calm before bedtime.

RENU Therapy clients have reported improved sleep since adding cold plunges into their daily routine. One reported reduced nighttime insomnia after plunging 4-5 times per week! This may be attributed to cold water's thermoregulatory effect that lowers body temperature while stimulating endorphin production - try plunging earlier in the day or waiting 1-2 hours prior to going to bed for optimal results.

5. Reduced Stress

Cold plunges have become an annual New Year's tradition dating back over one hundred years and are increasingly accepted within society, popularly practiced by athletes, influencers and others who claim that submerging into teeth-chattering temperatures helps reduce muscle soreness, strengthen immunity, aid recovery from injuries faster and alleviate depression and anxiety. Furthermore, some claim it improves energy and mental clarity - all qualities valued in an ideal New Year tradition!

However, not everyone should attempt this challenge; in particular if you suffer from an underlying heart condition or arrhythmias. Swimming in cold conditions could prove fatal; before embarking on this endeavor, consult with a medical provider first to assess your suitability for this challenge.

6. Increased Energy

Cold plunges have become popular with celebrities, athletes and TikTok influencers for quick soaks in cold water - often winter oceans or lakes, bathtubs or specially designed tubs - popularized by celebrities, athletes and TikTok influencers. A 2023 study discovered that cold water immersion (CWI) improved muscle soreness and perceived recovery 24 hours post high-intensity exercise while simultaneously decreasing creatine-kinase (a marker of muscle damage).

Short exposure to cold water can increase metabolism by making you shiver, which burns calories. Over time, prolonged cold water exposure may even increase brown adipose tissue which helps regulate body temperature while burning calories at the same time.

7. Reduced Depression

There's little scientific support for some of the purported health benefits associated with taking part in cold plunges - jumping into near-freezing bodies of water without freezing!- but brief immersion may result in increased levels of dopamine and noradrenaline (hormones and neurotransmitters known to promote alertness and pleasure), and one case study even found that an individual suffering from depression saw his symptoms diminish after starting regular cold-water plunge sessions.

Many polar bear dippers swear the cold plunge increases their energy, reduces muscle soreness and aids weight loss.

8. Reduced Anxiety

People suffering from anxiety who take regular cold plunges have reported less intrusive thoughts, improved mood, and greater clarity. Before undertaking this practice to relieve their symptoms of anxiety however, it's wise to consult a medical provider first.

Immersing oneself in cold water triggers neurotransmitters that regulate emotions and stress. Regular cold plunges also increase norepinephrine levels to help ease anxious thoughts - likely why many who take part claim it helps ease their anxiety.

9. Increased Norepinephrine

Your body responds to taking a cold plunge with an increase of norepinephrine and dopamine - hormones and neurotransmitters associated with alertness and pleasure - that help explain why many describe post-plunge experiences as giving them an "extreme high."

Voluntarily immersing yourself in cold temperatures is challenging both your body and mind, which is why experts advise gradually increasing exposure time and frequency over time to build resilience. Consistency is also key as it takes several weeks for your body to adapt to cold temperatures.

10. Increased Oxygen

Cold water immersion causes your baseline levels of noradrenaline and dopamine--hormones and neurotransmitters linked to alertness, motivation, mood, learning capacity and recovery--to spike significantly, while stimulating endorphin release resulting in improved mood and feelings of well-being.

As soon as you enter cold water, blood vessels constrict and pull blood closer to the core. But once out, they relax and open again releasing an abundance of oxygen into circulation that boosts it further. Repeated use can even result in microvascular adaptations that optimize long-term circulation.

Information provided by ReGen Bodylab is for educational purposes only. Your health and wellness is unique to you, and the products and services we review may not be right for your circumstances. We do not offer individual medical advice, diagnosis or treatment plans. For personal advice, please consult with a medical professional.

ReGen Bodylab adheres to strict editorial integrity standards. To the best of our knowledge, all content is accurate as of the date posted, though offers contained herein may no longer be available. The opinions expressed are the author’s alone and have not been provided, approved or otherwise endorsed by our advertisers.