Does Cold Plunging Work?
- Aug 27, 2025
- 3 min read
Overview
Although cold plunging and alternating hot-cold immersion (contrast hydrotherapy) have long been accepted as viable methods to speed up post-exercise recovery, the practices have also gained popularity in the general population in recent years. Despite the method’s rising prevalence, the mechanism of cold plunging’s alleged benefits is still not fully understood and benefits among the general population, in particular, remain understudied and unproven.
Mechanism
The predominant mechanism behind cold plunging and contrast hydrotherapy is driving a pattern of vasoconstriction and vasodilation (the widening and narrowing of blood vessels). This mechanism can decrease swelling and thus promote muscle recovery.
Cold Plunging
After injury and exercise, swelling can cause discomfort and increased recovery time. Generally, swelling refers to the movement and retention of blood, immune cells, and other metabolic factors in an area of injury or stress. After cold plunging, the lowered body temperature causes vasoconstriction, which decreases this movement, thus reducing swelling and inflammation.
Contrast Hydrotherapy
Similarly, contrast hydrotherapy serves to decrease swelling and inflammation but does so with a “pumping” mechanism. As discussed above, vasoconstriction occurs during the cold exposure, however, the hot exposure causes vasodilation and an increase in blood flow. Movement between these two states ensures that helpful metabolites (such as oxygen and antioxidants) are brought to the site of injury or stress and harmful metabolites (like lactate) are cleared away while also preventing metabolites from stagnating and causing inflammation.
Benefits for Athletes
Cold plunging and contrast hydrotherapy have been shown to be effective in speeding recovery for athletes, especially for those who train so often that their bodies do not have time to recover in between sessions.
For the reasons mentioned above, cold plunging can reduce swelling, thus increasing the rate of recovery. Cooling the body also decreases nerve conduction and muscle spasming, leading to less muscle pain.
However, if you are exercising no more than every 48 hours, your body likely has time to recover between sessions and cold plunging may offer fewer benefits.
Additional Benefits
Some people hypothesize that cold plunging has additional benefits, even for non-athletes, such as revitalizing the psychological state, slowing metabolic rate, strengthening the immune system, and improving sleep quality and mood.
Unfortunately, there isn’t much conclusive evidence on these potential benefits. More research is needed to determine the mechanism by and extent to which cold plunging may affect aspects of health other than muscle recovery.
Other Considerations
Cold plunging does also have some downsides, and the effects, both positive and negative, vary from individual to individual.
In the same way that vasoconstriction slows swelling, the process can also slow the uptake of dietary protein, thus decreasing the post-exercise muscle-building response.
The rate at which a person’s core body temperature changes depends on body mass and body fat percentage, so not all individuals will see the same effects after cold plunges of equal lengths of time. If you are participating in cold plunging, find a time and frequency that works best for you personally, rather than taking cues from others who may have different body types.
Although cold showers are often said to promote health in a variety of ways, they are not as effective as cold plunges in lowering core body temperature and may have a different mechanism of action.
Some of the benefits of cold plunging, such as lactate clearance, can also be achieved by active recovery methods, which may be more accessible.
Summary
Although the benefits of cold plunging in the general population are still not well understood, the method has been shown to promote recovery in athletes, and future research may uncover additional positive effects.
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