It sounds chilling, but some people, especially professional athletes, hop into an ice bath after a workout. After the initial shock of dipping your muscles into icy cold water, you might wonder what benefit a cold water immersion offers. Can it speed up muscle recovery after a tough workout?
What is an Ice Bath?
Stepping into an ice-cold bath after a workout is a form of cryotherapy. The idea behind cryotherapy is that exposing muscles to cold water helps flush waste products out of the muscle. Even ice packs you place on a sore muscle are a form of localized cryotherapy. Some athletes even have access to whole body cryotherapy where they expose their body to temperatures of -100 degrees C. after a workout.
How does cryotherapy work? During intense exercise, muscles build up waste products, including lactic acid. The theory is that cryotherapy helps your body remove waste products that interfere with muscle recovery. Exposing muscles to cold water may also slow the metabolic processes inside the muscle and minimize muscle swelling. Once you step out of an ice-cold bath, blood flow increases and the healing process begins.
Does Science Support Ice Baths and Cryotherapy?
Whole-body cryotherapy shows the potential for treating some inflammatory conditions such as rheumatoid arthritis. For example, studies show that spending 2-5 minutes in a whole body cryotherapy tank reduces the release of inflammatory chemicals called cytokines that are linked with pain and inflammation.
Since it reigns in the release of inflammatory cytokines, whole body cryotherapy sounds like a good option for muscle recovery after a workout. We’re all familiar with the phenomenon known as DOMS or delayed-onset muscle soreness. It’s the all-too-familiar muscle aching and stiffness you feel after a novel workout or one that your muscles haven’t adapted to. Eccentric exercise causes the most pronounced delayed-onset muscle soreness.
Despite its appeal, assuming you don’t mind cold temperatures, there is a lack of strong evidence that cryotherapy works. Studies show that athletes who use whole body cryotherapy feel better after a session but it’s not clear whether cryotherapy improves functional capacity or reduces workout muscle soreness due to DOMs. There are small studies showing temporary, modest benefits from whole body cryotherapy but few high-quality randomized clinical trials showing benefits.
What about a less high-tech form of cryotherapy, like ice baths or applying an ice pack to a muscle? One meta-analysis of 22 studies found that ice offered modest benefits for ankle sprains and after surgery. So, for soft tissue injury, ice doesn’t seem to have robust benefits, despite being a therapy many sports center use. However, there aren’t a lot of high-quality trials that have looked at the issue.
On the plus side, one meta-analysis of 36 studies found some improvement in the symptoms of delayed-onset muscle soreness after cold water immersion. However, the improvement in symptoms was restricted to the first 24 hours and there was no enhancement of muscle performance when subjects exercised afterward. Therefore, the benefits are short-lived and subjective. Cold water immersion doesn’t seem to improve muscle performance.
Another study looked at the effects of massaging a muscle with ice after eccentric exercise. Again, the results were not persuasive. The ice massage did little to enhance muscle recovery.
Are There Risks of Using Ice Baths or Cryotherapy?
Cryotherapy may be over-hyped, but it’s safe, right? Although there are few reports of adverse effects from immersing a body in cold water, it could be unsafe for certain individuals, including those with cardiovascular disease and those who have a blockage of arteries that lead to the brain. Your nervous system reacts to immersion in cold water by releasing factors that constrict blood vessels. In response, your heart rate, blood pressure, and breathing rate rises. For people with blockages in their arteries, this isn’t safe. Plus, blood flow to the brain drops when you immerse your body in cold water.
Also, prolonged blood vessel constriction due to longer periods of cryotherapy deprive tissues of blood and oxygen. In extreme cases, this can lead to tissue death. Plus, there’s some evidence that blood vessel constriction persists even after the cold application is over. Therefore, anyone with a history of cardiovascular disease, stroke, diabetes, or peripheral vascular disease should avoid ice baths or whole-body cryotherapy. Some research suggests that cryotherapy may reverse the flow of lymph through lymph vessels, thereby triggering inflammation and potential cell death or reduce a cell’s ability to repair.
Another risk you may not have considered: there’s some evidence that applying cold to a muscle after a workout can delay healing of an injury by blocking inflammation. Chronic inflammation is a negative in terms of health, but short-term inflammation in response to an acute injury is beneficial. It’s inflammation that recruits immune cells to the area to help the area heal. Without this response, it could delay healing.
But there’s another concern. Some research suggests that cold water immersion after a workout may interfere with muscle growth. In one study, a group of cyclists sat in cold water for 10 minutes after each workout. Another group did an active recovery on a stationary bike for 10 minutes. When researchers measured muscle mass using MRI along with their strength after 3 months, the group that sat in cold water experienced less gain in muscle mass relative to the group that did an active recovery. Research suggests that cold immersion and ice baths may interfere with the activity of genes and signaling pathways that promote muscle hypertrophy.
The Bottom Line
The downsides of ice baths may outweigh the benefits. The positive impact on muscle discomfort is short-term and the potential risks, including interference with muscle hypertrophy are concerning. The best approach might be to do an active recovery and stretch rather than jumping into an ice bath.
· Open Access J Sports Med. 2014; 5: 25–36.
· The American Journal of Sports Medicine 32.1 (2004): 251-261.
· J Sports Med Phys Fitness. 2003;43(4):500-505.
· Am J Sports Med. 2004;32(1):251-261.
· Osteopractic Physical Therapy. “Whole Body Cryotherapy: Counterproductive to Tissue Healing for Exercise-Induced Muscle Damage”
· Temperature (Austin). 2017; 4(3): 211–213.