What is Contrast Therapy—and How It Impacts Recovery

The circulatory system is a network of more than 60,000 miles of blood vessels that keep blood flowing to and from the heart continuously. Arteries transport oxygenated blood and vital nutrients away from the heart to tissues throughout the body, providing necessary fuel for cellular processes and peak performance. 

Deoxygenated blood that contains waste products, including carbon dioxide, is carried back to the heart from various tissues through the veins, where it can be re-oxygenated and cycled back through. The capillaries are a third type of blood vessel that connect the veins and arteries. The thin walls of the capillaries allow materials to be transported to and from the blood and tissue cells in the body, including oxygen, nutrients, carbon dioxide, and other waste products.

The circulatory system is tirelessly at work 24/7 to keep the body functioning properly. Certain activities, like intense workouts, kick its actions into high gear. A regular fitness routine can lead to a higher-functioning circulatory system, which isn’t just ideal for exercise performance but also for overall health, and may increase longevity. Efficient blood flow reduces injury risk, boosts immune health, supports healthy tissue, decreases the likelihood of dealing with sore muscles after exercise, and increases healing times following injuries and surgeries. 

Efforts to improve blood flow and circulation are not limited to regular exercise. Other popular activities that act on the circulatory system and give the body a boost include staying hydrated, adopting stress-relief strategies, eating a healthy diet, and reducing the amount of time spent sitting each day. Contrast therapy is another example of an activity that is growing in popularity as a post-workout recovery strategy, which works at least in part by stimulating the circulatory system. 

In this article, discover more about contrast therapy and its benefits when combined with a regular fitness routine.

What is Contrast Therapy?

Contrast therapy, commonly referred to as contrast bath therapy or immersion therapy, is a practice used by physical therapists, athletes, exercise and wellness enthusiasts, and popular in spa offerings these days, and across many cultures including much of Europe, that involves alternating the body’s exposure to hot and cold water. The ‘contrast’ in this recovery strategy refers to the extreme temperature difference between the hot and cold water. 

Contrast therapy stimulates two physiological processes: vasodilation and vasoconstriction. During vasodilation, dilation of the walls of the circulatory system’s blood vessels occurs, increasing blood flow. Heat exposure is one common cause of vasodilation. In contrast, vasoconstriction involves the narrowing and constricting of the blood vessel walls and can happen in response to cold temperatures. 

When contrast therapy is performed, there is a swift alternation between hot and cold exposure and vasodilation and vasoconstriction as a result. Contrast therapy causes the blood vessels to dilate and then contract in quick succession, resulting in a pulsing action in the blood vessels. This occurrence has been referred to as the vascular pumping effect, which is theorized to boost the rates of blood flow and oxygen to the tissues directly impacted by hot and cold exposure. 

This increased flow of oxygenated blood may result in more efficient waste removal, heightened functionality, and improvements in healing and recovery. 

One study found a contrast bath protocol applied to the lower leg of 10 participants was associated with changes in the oxygenation of the leg muscle, supporting the theory that contrast therapy induces a vascular pumping effect that increases oxygenation of muscles in the targeted area. 

Benefits of Contrast Therapy

Contrast therapy is becoming a popular part of post-workout and recovery routines in order to boost recovery and support peak performance. Benefits of contrast therapy include:

Decreased Post-Workout Soreness

One of the reasons contrast therapy is quickly becoming a go-to for post-workout recovery routines is its capability to mitigate delayed-onset muscle soreness. Studies have found that contrast therapy was able to reduce the experience of muscle soreness following exercise significantly, and was more effective than passive recovery. 

Reduce Swelling and Pain

Contrast baths have also been found to reduce swelling and pain in targeted areas, making them a valuable recovery tool. When there is a muscular injury in a particular area, the body’s inflammatory response is activated. 

More blood courses through the circulatory system to the area, carrying white blood cells and extra fluid to stave off infection and promote healing. This increase in blood flow and fluids causes redness, swelling, and often results in pain. The alternating vasoconstriction and vasodilation achieved through contrast therapy promotes more efficient blood circulation in the area of injury, decreasing swelling and pain.

Less Fatigue

Contrast therapy can be used to lessen feelings of post-workout fatigue and return the body to a performance-ready state more quickly than it can on its own. Research has found that contrast therapy can help you recover within 48 hours following high-level exercise and feel less fatigued within 24 hours. 

Promotes Healing

By improving blood circulation in targeted areas, contrast therapy can also activate and speed up the body’s natural healing process. Efficient blood flow is essential for proper tissue health by ensuring the delivery of oxygen and nutrients to tissues and removing waste products. Contrast therapy improves circulation and blood flow to tissues, promoting tissue health and reducing the risk of injury. When injury occurs, healthy tissues can heal more quickly, thanks to the circulatory benefits of contrast therapy.

Cognitive Benefits

Contrast therapy can have a positive impact on both physical and mental health. Both heat and cold exposure are known to stimulate the release of chemicals in the brain associated with positive feelings and improved cognitive function. Heat immersion releases prolactin, beta-endorphins, and norepinephrine, while cold exposure leads to a rush of dopamine, adrenaline, serotonin, and norepinephrine. 

When paired together, dual exposure to extreme temperatures boosts focus, attention, motivation, memory, and mood. Contrast therapy can help you achieve a clearer state of mind, supporting enhanced concentration and cognition. 

All in all, contrast therapy is a useful strategy for getting the mind and body into optimal shape for performing at a high level and increasing general wellness and overall health.

How to Practice Contrast Therapy 

Contrast therapy can be done in several ways, but the ratio of time spent in hot to cold water immersion is typically the same in each type. For every three to four minutes of heat exposure, there should be one minute of cold exposure. Most people begin with heat immersion, followed by cold. Contrast therapy sessions are usually between 20-30 minutes, during which you continue to alternate between these short periods of hot and cold exposure. 

Contrast therapy can be achieved with the following heat/cold exposure combinations:

• Hot/Cold Shower
• Hot Shower/Cold Plunge
• Infrared Sauna or Steam Room/Ice Bath

When practicing contrast therapy for the first time, it’s recommended to have professional oversight and consult with a medical provider to ensure this recovery strategy is advisable. Individuals with certain health conditions such as cardiovascular disease, diabetes, high blood pressure, and neuropathy are not advised to practice contrast therapy. Hot and cold immersion are also not suitable for individuals with active infections, fevers, or open wounds. 

How WHOOP Measures Contrast Therapy

WHOOP Recovery allows members to track specific recovery activities, ranging from meditation to stretching to sauna and cold therapy. WHOOP measures the body’s response to these recovery efforts and gives personalized insight into its recovery impact.

By inputting hot and cold exposure as recovery activities or tracking them within the WHOOP Journal, WHOOP members can track contrast therapy and its impact on the body.

Research conducted by WHOOP has found that members frequently pair hot and cold therapy techniques as part of a recovery program. Among WHOOP members, cold therapy was more likely to be paired with hot therapy. Around 30% of cold therapy enthusiasts also participated in hot therapy, while only 16.6% also practiced cold therapy. 

Log your recovery activities with WHOOP to get the data-driven insights you need to unlock your best performance.