Depending on your tolerance for extreme temperatures, immersing your body first in hot water and then in an icy cold bath may sound either invigorating or torturous.
Contrast hydrotherapy involves alternating hot and cold water treatment. The practice has many fans, including athletes who say it gets them back in the game faster.
Here’s a look at the science behind this popular therapeutic intervention.
The key to contrast bath therapy is in the rapid changes produced in your circulatory system when you go from very warm water to very cold water.
When you submerge part or all of your body in cold water, small blood vessels called capillaries respond to the cold by getting smaller. This is known as vasoconstriction.
When you immerse yourself in warm water, the opposite happens. Your blood vessels open up. This is known as vasodilation.
Different water temperatures also cause changes in how fast your heart beats.
So, how do these circulatory changes help you?
When you rapidly alternate between hot-water and cold-water immersions, your blood vessels open and close in a pulsing, pump-like motion. Some proponents think this pumping action can help relieve various injury symptoms.
Contrast bath therapy is considered a passive form of therapy. Aside from some gentle motions you might perform, you aren’t actively moving or stretching your muscles as part of this treatment.
Even so, there is some evidence that contrast hydrotherapy could help with certain conditions and symptoms. Here’s what the evidence has to say.
Athletes might find that contrast hydrotherapy helps alleviate post-game fatigue.
Immersion in cold water alone didn’t provide the same benefit.
Decreases muscle soreness
Intense exercise causes damage to your muscle fibers. But you might not feel sore until a day or so later. This is called delayed onset muscle soreness (DOMS).
Researchers measured both DOMS and muscle weakness in elite athletes following strenuous workouts. They
Two factors should be noted.
- First, researchers found that the best results happened when the hot water temperature was lower than 104°F (40°C).
- Second, other popular therapies, such as immersion in cold water alone, were about as effective at relieving these symptoms as contrast bath therapy was.
Removes excess lactic acid
When you exercise vigorously, lactic acid builds up in your body. The accumulation of lactic acid is normal, but it can make you feel tired and sore.
You can ease the symptoms of lactic acid buildup in your body by resting, drinking water, taking a magnesium supplement, and following a few other simple protocols.
When you get injured, part of your body’s normal inflammatory response is a rush of fluid and white blood cells to the injured area. The buildup of this fluid can exert pressure on the injury and cause pain.
There is some evidence that contrast baths reduce swelling. In a 2016
People who use contrast bath therapy usually do so with the help of a physical therapist or athletic trainer.
In a physical therapy or rehabilitation clinic, your therapy session could involve whole body immersion in different whirlpools or tubs. Or it could involve a more targeted intervention in which you submerge only your injured body part.
Your therapist could also instruct you to perform some gentle exercises while you’re in the water.
Though many people do contrast therapy while supervised by a professional therapist, it’s possible to try it on your own. Check with your doctor first to make sure it’s safe for you.
- two containers or tubs large enough to submerge either your whole body or your injured body part
- a thermometer to measure the water temperature
Water in the cold container should be between 50-59°F (10-15°C), and water in the hot container should be between 95-113°F (35-45°C).
Once you have the water ready at the correct temperature, take the following steps:
- Immerse either your entire body or the injured body part in warm water for 1 to 3 minutes.
- Immediately follow with a 1-minute dip in cold water.
- Repeat this process for approximately 20 minutes, ending with cold water.
The primary risk of contrast bath therapy is that you could damage your skin if the water temperature is either too hot or too cold. It could also cause a heart arrhythmia.
Contrast bath therapy isn’t safe for every condition. It’s important to talk to your doctor or healthcare provider before you try contrast hydrotherapy, especially if you’re thinking of immersing most of your body. This is especially important if you have:
- open wounds
- heart issues
- high blood pressure
- deep vein thrombosis
Contrast bath therapy is a series of brief, repeated immersions in water, alternating between warm and cold temperatures.
Research supports the use of contrast hydrotherapy to lessen muscle fatigue and to decrease pain, swelling, and lactic acid buildup following intense exercise.
You can use contrast hydrotherapy under the supervision of a trained therapist. Or you can try it at home by dipping your body or the injured body part into warm water for 1 to 3 minutes, then switching to cold water for 1 minute, and repeating the process several times.
There are some risks for people with certain conditions. Be sure to talk to your doctor before you try this intervention on your own.