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What Is Contrast Therapy?

Contrast bath therapy, sometimes called contrast bath therapy, involves alternating heat exposure with cold exposure using water. This practice has risen in popularity for the numerous body and brain benefits. Alternating hot and cold exposure can be achieved in two primary ways, one using only water and another using a hot sauna before cold water immersion.

Contrast bath therapy is a recovery intervention that produces rapid changes in your circulatory system by triggering increased blood circulation. This is achieved by transitioning between hot and cold water. An essential principle is always starting with heat therapy first and ending with cold therapy.

When you submerge part or all of your body in cold water, it induces the small blood vessels called capillaries to get smaller, a process called vasoconstriction.

Immersing yourself in warm water creates the opposite effect in the circulatory system, causing the blood vessels to rapidly open up, a process known as vasodilation.

Alternating hot and cold water temperatures also cause fluctuations in heart rate. In general, cold water immersion causes the heart rate to speed up and hot water causes it to slow down.

Beyond the cardio benefits, what other health benefits can come from contrast bath therapy?

What's The Difference Between Contrast Water Therapy and Contrast Therapy?

Research indicates the best contrast hydrotherapy results happen when hot water temperatures stay below 104°F (40°C), or about the temperature of the average hot tub. But remember, this only applies to contrast water therapy, which differs from contrast therapy—combining a hot sauna with a cold water immersion tub.

Compared with hot baths for hydrotherapy, hot saunas produce a dry heat that's around 180ºF, creating a far different experience. Although the temperatures are higher, you'll stay in a hot sauna for around 20 minutes before cold-plunging, which is nearly double the time you should stay in hot water.

One significant advantage of hot saunas over hot tubs is that you breathe in hot, dry air when using a hot sauna, which brings the heath therapy benefits into your airways as well.

What Are The Health Benefits Of Combining Hot And Cold Water Therapy?

Fatigue Reduction After Intense Exercise

Many athletes claim contrast hydrotherapy alleviates their post-game and training fatigue. A 2017 meta-analysis of research studies on contrast bathing found team sports players who followed a routine of alternating hot and cold baths recovered from their fatigue in only 24-48 hours after their game or training session. However, immersion in cold water alone didn’t deliver the same active recovery benefits.

Facilitating Recovery By Reducing The Severity Of Muscle Soreness

Exercise-induced muscle damage is no joke, and one of the best physical therapy measures for recovering afterward is contrast water therapy.

Feeling sore a couple of days after intense exercise is known as delayed onset muscle soreness (DOMS). To help with this, ice-cold baths following a hot tub plunge or hot sauna session can improve blood circulation, reducing DOMS.

Researchers who measured DOMS effects in elite athletes after they performed strenuous workouts found contrast bath therapy helped alleviate the severity of their delayed onset muscle soreness, along with the associated weakness. It was also found to be more effective than passive recovery alone.

Intense exercise causes muscle damage at the fiber level, causing deep pain and stiffness, increasing the possibility of pulling a muscle or joint injury. Part of the DOMS recovery process involves pain management when the body is trying to heal the damaged muscle tissue.

Flush Away And Prevent Lactic Acid Buildup From Muscles

Strenuous exercise causes a build-up of lactic acid in the body. While this lactic acid accumulation is normal, it can result in having chronically sore and tired muscles. The effects of excess lactic acid can be remedied by resting, drinking water, taking magnesium supplements, and implementing a regular contrast therapy routine.

Two research studies in 2007 found that contrast therapy helps decrease lactic acid levels in the body after working out intensely, helping athletes recover from their soreness and fatigue following the strenuous exercise much better than using passive recovery techniques like resting alone.

Promoting Lymphatic Pumping Action For Detoxification

By switching from sitting in a hot sauna or hot tub to taking a cold water plunge, your body triggers the lymphatic system to start working overtime. The system quickly starts flushing away any harmful toxins you may have in your system, along with helping to promote the regeneration of healthy cells throughout your entire body.

Improved Blood Circulation With Contrast Baths

By cycling between hot and cold environments, your body naturally increases blood flow by the pumping action caused by alternating between constriction and dilation of blood vessels. This pumping action improves vascular and cardiac response and overall health.

Speeds The Healing Process For Sports Injuries And Overworked Joints

When you have muscles and joints that have suffered injuries, your body’s response is to flood the injured areas with a tide of restorative fluids and white blood cells. But while these fluids are necessary, they can build up to levels that create more pressure on the injury, causing you painful swelling and joint stiffness.

Based on evidence from a 2016 study involving 115 people with ankle sprains, contrast hydrotherapy could help you with pain relief from sports injuries. In the study, contrast water therapy lessened swelling for participants in only three days post-injury on average.

May Lower The Likelihood Of Alzheimer’s Disease And Dementia

In a study conducted by the University of Eastern Finland over 20-years with more than 2,300 participants, Dr. Jari Laukkanen and colleagues found that using a sauna regularly for 4-7 times per week at 176 degrees F for 19 minutes lowered the risk for Alzheimer's disease, along with Dementia. Keep in mind, this 20-year study used hot saunas, not hot tubs that could be used in contrast hydrotherapy.

Helps Keep Skin Clear And Looking Young

When skin temperature drops during the cold phase of contrast therapy, skin pores minimize, slowing blemish-causing oil production. This process helps reduce the occurrence of acne, pimples, and blackheads. When blemishes are on the skin, contrast therapy helps reduce swelling and redness, providing soothing relief for irritated skin.

Does Contrast Hydrotherapy Work For Lowering A Fever?

With the rise in popularity of contrast therapy routines, many people may wonder if another health benefit includes reducing a fever.

Although the cold exposure at the end of contrast therapy may seem like an easy way to lower the body temperature of someone that has a fever, it's unclear whether either using cold immersion or contrast bath therapy is an effective form of treatment.

Uncertainty remains among researchers when it comes to using hydrotherapy treatments for fever reduction.

While cold water immersion when running a fever seems like a simple way to drop body temps fast, the opposite could actually be true. When plunged into frigid waters, the body induces cutaneous vasoconstriction, shivering, and sympathetic system activation. All responses that could raise body temperature.

While some cold water immersion is effective for many physiological and therapeutic treatments and health benefits, the scientific research is still unclear on fever reduction or hyperthermia reduction.

Research On Using Ice Packs Or Cold Water Therapy For Fever

One recent study f0und that placing ice packs in the neck or groin areas isn't effective for treating hyperthermia. That said, hyperthermia isn't the same as running a fever—it's much more serious.

Hyperthermia is when the body temperature rises above a safe range that's controlled by the hypothalamus. Heatstroke is one form of hyperthermia.

However, with a fever, the hypothalamus is working to raise the body's temperature.

Can Cold Water Therapy Help Children With A Fever?

It's still unclear whether causing the discomfort of cold water immersion for young children is justified by a reduction in complications stemming from a high fever, such as febrile seizures, and whether this form of external cooling of seriously ill patients is actually associated with lower morbidity than treatments using only antipyretic drugs.

Answers to these types of scenarios are important because of the potential negative side effects of cold exposure, such as shivering, hypermetabolism, pneumonia, pressure sores, and other complications that can arise if sedating and paralyzing drugs are used for the reduction of shivering.

More Research Is Needed Regarding Contrast Bathing For Fever Reduction

Practicing cold water therapy or contrast bath therapy for reducing a fever still needs more research using multiple types of clinical studies instead of using simple comparisons of rates of core temperature cooling alone.

What Are The Health Risks Of Contrast Therapy?

Although contrast therapy is safe for the majority of folks, there are some who should refrain from the practice. For example, people who have heart conditions should choose milder temperatures and avoid extremes on each end of the temperature range.

Cold receptors in the face and scalp sense quick drops in temperature, which results in a diving reflex—a type of cardiorespiratory response that can cause shortness of breath, decreased cardiac output, and a rapid decrease in pulse. If these symptoms pop up, it's best to take a break and consult with your physician before trying again.

What Equipment Do You Need For Contrast Therapy?

If you want to try contrast therapy, what equipment do you need?

- Two tubs that allow you to submerge your entire body
- A thermometer to monitor the water temperature constantly
- Towels close by for fast drying and warming back up
- Water temperatures for the cold immersion tub should stay between 39-55°F, and between 95-113°F for the hot water contrast therapy tub. Hot saunas should be around 180ºF.

In a meta-analysis study of the results of numerous contrast therapy studies, 95 percent of the water temperatures during the tests remained within the above-recommended ranges for both hot and cold water. This is a perfect example of why it's important to use a thermometer to monitor the water temperature. Preventing accidental burns or exposure to dangerously cold water that can drop skin blood flow rates to low levels can cause both pain and damage to delicate skin tissue.

What Is The Best Way To Benefit From Contrast Therapy?

How To Properly Take A Cold Plunge After Hot Sauna Sessions?

The best form of contrast therapy combines a hot sauna with immersion in a cold tub or ice bath directly after. The benefits are substantial, and they've been used in numerous cold climate cultures for decades, such as the Finnish. Let’s run down the list of quick tips for effective and safe contrast therapy so you can enjoy the benefits while keeping risks at a minimum.

Tips For Contrast Therapy With A Hot Sauna And Cold Water Immersion Tub

Always start with the hot sauna session first. Also, make sure to set the temperature of the ice bath to between 39-55ºF for optimal benefits. RENU Therapy cold tubs maintain an accurate and steady 39-55°F based on your preferences.

Many hot saunas enable you to set the temperature between the safe range of 150-190°F, so try what feels best for you. Keep both the units close by to minimize any delay between switching from hot to cold.

Once your hot sauna and ice bath are at the optimal temps, follow these steps:

1. Take a cold plunge in the RENU ice bath for a few minutes

2. Next, sit in the hot sauna for twenty minutes

3. Immediately follow this with a plunge in the cold water for a few minutes again

4. Repeat this cycle if desired, always ending with a cold water plunge

Enjoy Convenient Contrast Therapy With RENU

RENU crafts beautiful cold plunge tubs 100% in the USA. RENU provides every customer with the best warranty coverage on the market along with striving for 100% customer satisfaction with every cold tub we sell!

We offer a wide selection of cold plunge tub design options to enable you to perfectly match your home's aesthetics. Each of our ice bath therapy tubs boasts world-class designs that enhance the charm and beauty of your space, whether business or residential.

Contrast Therapy When You Need It Most

Contact RENU today and find out more about combining one of our hot saunas with our cold plunge tubs at home!

Frequently Asked Questions

What is contrast water therapy?

Contrast water therapy, also referred to as contrast bath therapy, is the practice of alternating from heat exposure to cold exposure using water. This practice has risen in popularity for the numerous body and brain benefits. 

Alternating hot and cold exposure can be achieved in two primary ways, one using only water (contrast water therapy) and the other using a hot sauna before cold water immersion.

Contrast bath therapy is a recovery intervention that produces rapid changes in your circulatory system, triggering increased blood circulation. This rapid change may induce many types of health benefits, including faster training recovery times, alleviation of pain, and a more peaceful mental state.

What are the benefits of contrast water therapy?

Contrast water therapy can provide a host of benefits for regular practitioners. When it comes to maximizing athletic performance, boosting overall physiological resilience, and promoting cardiovascular health, few other methods can deliver so many benefits in one therapy modality. 

Here’s a list of how you may benefit from contrast water therapy:

- Helps reduce feeling fatigued - after intense exercise

- Facilitates recovery by reducing the severity of delayed onset muscle soreness

- Flushes away and prevents excess lactic acid buildup in the muscles

- Promotes lymphatic system pumping action for detoxification

- Improves blood circulation and cardiovascular performance

- Speeds up the healing process for sports injuries and strained joints

- Could lower the likelihood of Alzheimer's disease and dementia

- Promotes a healthy mental state and sense of well-being

- Helps keep skin looking clearer, firmer, and more youthful

When should contrast therapy be used?

Contrast therapy can be practiced just about any time, with many people making it a daily routine. The best time for a contrast therapy session is directly after an intense workout, which will help prevent post-workout soreness and inflammation.

There are some times when contrast therapy shouldn’t be practiced, such as when you’ve suffered from heat stroke (hyperthermia) or when you’ve suffered injuries to the skin that may be adversely affected. Also, when you’ve been dealing with cardiovascular issues like a heart attack recently, it’s best to avoid extreme swings in temperature. Always consult your doctor before starting contrast therapy.

How often should you do contrast baths?

Contrast baths can be taken every day when you enjoy the many benefits. In fact, the more regular and frequent your contrast bath therapy sessions, the greater the long-term benefits. Many of the studies conducted on using contrast bath therapy have found significant differences between those who only dabble in the practice off and on and those who perform it at least four days a week on average.

With that said, everyone has a different response to contrast therapy. While most people don’t have any trouble hopping into a nice hot bath, many people find it difficult to take a polar plunge into frigid bath waters. It’s best to take things at your own pace when getting started to ensure your ability to maintain the practice long-term.


Jim O'brien

Cleobella fashion

"A mood changer, a holistic approach to feeling better, and one of the pillars from Wim Hof's breathing books." 

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Scott Empringham

Founder of Empringham Media

"My energy is through the roof, my immunity is fantastic. I just feel fantastic."

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Molly Laing

Health Enthusiast, Cleanse Counselor and Health Coach

"If you are thinking about purchasing one of these cold plunge pools, I highly recommend the Renu Therapy product"

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Renu Therapy Ice Bath Tubs For Sale

Renu Therapy's ice bath tubs are 100% hand-made in the United States. They also come with the best warranty and have 100% customer satisfaction!

You won't need to prepare a cold tub by loading your bathtub with ice from an ice machine. You don't even have to think of ways to DIY your CWI. Renu Therapy's ice bath tubs come in just the right size so you feel comfortable taking an ice bath.

They are also designed to become an integral part of your home so there's a model that fits your interior be it minimalist or grand. Browse through our products and choose an ice bath tub for sale to fit your needs.

To learn more about the body benefits of ice baths, contact us at Renu Therapy today.