Are ice baths and cold showers the perfect solution after exercise?
You’ve probably seen pictures of athletes plunging into ice-cold water after a workout… Since Wim Hof—known as the “Iceman”—popularized the practice, it has become widespread in the fitness world and has since spread to other fields. It’s worth noting that it’s said to have numerous benefits!
Stéphane Perrey, University of Montpellier and Marc Julia, University of Montpellier
Health benefits, stimulation of the central nervous system, improved muscle performance and post-exercise recovery… This strategy of active recovery following physical activity—a fundamental component of any serious training regimen—has emerged as one of the most popular approaches over the past decade.
While many athletes—both professional and amateur—use it, they aren’t necessarily well-informed about the actual benefits of this practice and its effectiveness. If the thought of jumping into a simple pool makes you cringe, you might have more questions… Ice baths, cold showers, or a cryotherapy chamber at -80°C (at a specialized facility)—if you’re really motivated—are they truly beneficial? Or is it just a passing fad? Who can benefit from them?
To answer these questions, the best place to start is by looking at how cold affects our bodies…
A myriad of physiological responses
The most significant physiological adaptation to extreme cold is undoubtedly the narrowing of blood vessels, or “vasoconstriction, ” which is likely intended to reduce heat loss from the body. Ice baths thus cause a rapid short-term increase in blood pressure, which in turn leads to an increase in heart rate and respiratory rate.
Because blood vessels constrict, blood flow to the affected areas slows down significantly in terms of volume. This can be beneficial in combating excessive microbleeding and microinflammation caused by certain physical activities involving repeated impacts. If exposure to the cold continues, the tips of our nerve endings, just beneath our skin, can reduce sensation to the point of causing numbness.
There is also evidence that swimming in cold water can modulate the production of pro-inflammatory cytokines—small cellular proteins that trigger the body’s inflammatory response—which may have a pain-relieving effect.
But be careful: an ice bath shouldn't last long, due to the real risk ofhypothermia, which can have serious consequences.
What are the potential benefits?
Given these physiological changes, why do athletes choose this method after exercising? The most common reason is their belief that it will “heal” sore muscles.
What is well established is that ice baths reduce blood flow to the submerged areas, which helps reduce edema (swelling), aided by the effect of hydrostatic pressure. And, as mentioned, cold has an analgesic effect: this is useful in the case of a traumatic injury—hence the use of ice packs for localized injuries or to relieve postoperative pain. But be careful: cold does not heal; the pain will return when the temperature begins to rise. Its use is therefore only temporary and symptomatic.
And what about muscle pain after a strenuous workout? What about soreness? It has been suggested that, due to vasoconstriction of the blood vessels, muscle damage may trigger a weaker inflammatory response, resulting in less muscle pain.
Over the past 10 years, various studies have shown that immersion in cold water can, to some extent, help alleviate delayed-onset muscle soreness (24–48 hours). A study of elite rugby players, conducted over three weeks of competition, concluded that there was a reduction in muscle fatigue and a slight decrease in soreness. Separate research has also suggested a modest positive effect on muscle pain reported by MMA athletes. This was observed without any improvement in performance.
But… there is also evidence suggesting that cooling isn’t necessarily beneficial for post-exercise recovery—the perceived benefits may be due to a placebo effect (when we’re convinced it works). Cryotherapy (3–4 min at –85 °C), cold water immersion (10 min at 10 °C), and a placebo group were indeed compared following a strength training session. The differences were insignificant, and certain biological and performance markers even favored the placebo…
A meta-analysis also reported that the purported benefits of cold-water immersion (10 °C for an average of 13 minutes) appeared to be based more on subjective measures (perception of pain and perceived exertion) than on objective measures (blood markers).
In summary, cold water immersion—primarily due to its ability to lower tissue temperature and reduce blood flow—can reduce muscle pain and swelling, but its effects on recovery and muscle performance are highly debated. The beneficial effects on post-exercise recovery appear to be context-specific, and several factors—such as body composition, gender, the type of physical activity performed, and training status —must be taken into account.
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Friend or foe to the muscles?
Recent data has shown that post-exercise cooling can be detrimental when the goal is to build muscle mass (hypertrophy).
In fact, a study indicates that acute exposure to cold reduces the anabolism of skeletal muscle proteins (which promotes muscle growth) while increasing their catabolism (leading to breakdown). This has no effect on muscle strength.
Another study examined the effects of active recovery and ice baths on adaptations to strength training. After 12 weeks, ice baths reduced muscle growth… and strength gains! The acute (negative) effects of cold water immersion thus appear over the long term, perhaps due to a decrease in circulating testosterone.
If gaining muscle mass and strength is a goal (as part of a training plan, outside of competition periods), then cold water immersion should be avoided as a post-workout recovery strategy.
So… Should we take ice baths?
Potentially expensive and time-consuming, ice baths (10–15 °C for 11–15 minutes) are therefore not a cure-all…They can help reduce delayed-onset muscle soreness, but the same is true of active recovery, such as walking—which is cheaper and much easier to do!
While in the short term there is evidence of faster recovery of strength capacity, reduced inflammation, and less muscle soreness, over the long term, immersion in cold water appears to have no effect—positive or negative—on physiological adaptations.
Above all, cold water isn’t suitable for people following a strength training program—such as bodybuilders or weightlifters looking to build muscle mass and strength… But at the same time, they may find it beneficial to take advantage of the benefits of an ice bath after a very intense workout or competition.
So, how often you take a bath will depend on your exercise routine and your goals!
If you don’t need to build a lot of muscle, this approach might work for you. This applies to many athletes as well as combat sports. And even though strength and muscle mass are important, weigh the pros and cons… For example, in a competition spanning two consecutive days, with multiple sessions per day, the benefits of faster recovery will outweigh any reduction in muscle growth.
And you don’t need to take an ice bath after a low-intensity workout: your muscles won’t have sustained enough damage to warrant it.
Above all, if you have high blood pressure or a cardiovascular condition, an ice bath could be too much of a shock for you and your heart! You should consult a doctor. So be careful… As always, the key is to understand your body, your goals, and the effects of the techniques you use.
Stéphane Perrey, Professor of Exercise Physiology / Integrative Neuroscience, Director of the Research Digital Health in Motion Research Unit, University of Montpellier and Marc Julia, Sports Physician, Associate Researcher at STAPS, University of Montpellier
This article is republished from The Conversation under a Creative Commons license. Readthe original article.