Ice baths have been very popular for decades, with many athletes and coaches claiming that they help in rapid recovery. But what does the science say?
Exercise and Fatigue
Light exercise is just that: light. If you are going to do an easy 30-minute jog or gentle yoga, don’t bother: you won’t be fatigued enough to need recovery and cold-water baths will do nothing for you.
However, if you do strength training, hard speed work, or long runs, you may wish to consider cold-water baths immediately after exercise.
In this article, I will focus on the benefits of cold-water baths for running because it also involves an effect of outdoor temperatures, unlike indoor gym work.
A hard or long run, relative to your ability, causes microtears in the muscle fibres. This causes inflammation in the region, which brings swelling and pain. After a day, it can cause additional pain with what is called Delayed Onset Muscle Soreness or DOMS.
By the way, this damage is wrongly attributed by some experts to lactic acid buildup during the workout. That is incorrect science as lactic acid clears out so fast from the muscles that it cannot cause pain.
Cold-Water Bath or Ice Bath
- In a typical cold-water bath, a sportsperson sits in a bathtub filled with cold water or ice for between five and ten minutes.
- The word ‘bath’ is a bit of a misnomer here. You don’t stand under a showerhead and take a conventional bath.
- The word ‘ice’ is also a wrong moniker. An ideal ‘ice’ bath temperature is between 10–13 °C (50–55 °F).
- Usually, the head, neck, and upper torso are kept out of the tub, while the lower body is completely immersed in water.
- Arms are kept in the water or outside depending on whether arms were fatigued during the exercise.
Effects of Cold-Water or Ice Bath
Cold-water baths are thought to improve recovery through various mechanisms:
- Constricting Blood Vessels: In cold temperatures, the blood capillaries in the skin and peripheral muscles contract. They push local blood with inflammation byproducts into the veins and back towards the heart. This reduces inflammation in the muscle immediately and has been found to reduce DOMS a day later.
- Numbing Effect: The cold water decreases nerve conduction velocity, which reduces pain;
- Reducing Stress Hormones: A cold-water bath affects many hormones:
- It reduces cortisol, the stress hormone.
- It increases dopamine, making you feel good.
- It releases endorphins, the natural painkillers.
- The controversial part is that ice bath also increases noradrenaline, another stress hormone, which should theoretically make you more stressed.
Points to Note
- Science is still not clear on all benefits of ice baths. That is because the subjective feelings of reduced pain and improved recovery are far more common than objective measurements of reduced muscle damage and inflammatory chemicals.
- With an ice bath, the sudden fall in temperature can spike up the heart rate. So people with high blood pressure, heart disease, and even diabetes should avoid such baths.
- It is unclear how much the water’s coldness matters. One study showed that colder water was no better than room-temperature water for such baths.
- Some people overtrain—repeated heavy workout days without proper breaks or rest reduce heart-rate variability or HRV. As per the latest science, lower HRV is an indication of lesser cardiovascular fitness or the body being under stress. I will write about this important topic in another article. Ice bath increases HRV, which is a beneficial outcome.
- Post-exercise inflammation is a signal to the body to rebuild the muscle stronger, a goal in sports training. By reducing the inflammation, the improvement is less. This is noticed in ice baths after strength training.
- Athletes who use cold-water baths have consistently reported reduced pain and improved recovery.
- Actual measurements of the markers of pain, inflammation, and muscle damage have shown less consistent improvement with cold-water baths.
- A small study claims that the improvement is more in mind and less in physical terms—a placebo effect.
Post-exercise inflammation is a part and parcel of pushing the body to adapt and improve to a higher physical load. Reducing inflammation with cold-water baths is detrimental to that goal.
In the absence of hard data, my common-sense thinking is that ice baths should be used when the muscle damage is not intentional.
I would ask a question: “Why did I do this strenuous exercise?” There are four possible responses:
- “It was part of a competition“: Use an ice bath. If you had no choice but to push the limits, you would rather get back to training and a faster recovery is better.
- “I did for improving my fitness“: Don’t use an ice bath. If you exerted so hard, the purpose was to improve. Why would you limit those gains?
- “I did it for staying fit“: Use an ice bath. You overdid your exercise, which may improve your fitness, but that was not your aim. So why suffer post-exercise?
- “It was part of a recreational activity“: Use an ice bath. If the muscle soreness is due to a long trek or a cycling trip, you would get back to normal life quicker with ice baths.
To Read More
- Trail and Kale: The Benefits of Ice Baths For Runners
- New York Road Runners: Fact vs Fiction: Ice Baths for Workout Recovery
- Runners World: I Tried Taking Ice Baths for a Month and Here’s What Happened
- On this Website: Ice or Heat: What to Use for Muscle Pain?
First Published on: 15th July 2023
Image Credit: vwalakte on Freepik