If you are on social media, you have probably come across this video while scrolling: a person in a robe stands on their deck with several inches of snow covering the ground. They are using a hammer to break through the inch of ice that has formed on the giant tub full of water they are standing next to. Once the ice is broken up, the individual removes their robe and climbs into the frigid water. Often, the video then switches to a “timelapse,” showing the handful of minutes the person remains in the water.
If you are not on social media, or just not familiar, these “ice baths” have become popular amongst fitness and wellness junkies. But believers in the cold plunge feel it is much more than a social media trend. What used to be a once-a-year “polar bear plunge” at the end of your local winter 5K has become a daily health habit for many. Ice bath evangalists say the cold is life-changing.
Curious about the ice bath myself, I set out to understand more before I was baptized into the icy waters. Most importantly, I wanted to know if mountain bikers might see benefits in riding performance if they begin taking a regular plunge. And, if possible, can I find similar benefits without filling my bathtub up with ice?
Recovery after cardio
One benefit heard over and over again is cardio recovery, specifically easing the pain of sore muscles after a workout. You go on a long pedal, and as a result, your muscles are sore. Or, maybe it isn’t so much the mileage you put in, but particularly chunky and fast descents that create the dreaded arm pump. Infrequent bike park days can leave you barely able to move!
So why do we get muscle soreness in the first place? It is likely that the soreness we experience afterward is a result of lactic acid build-up, spasms, tissue damage, or inflammation. In reality, it could very well be a combination of all of these.
Whether you experience two, three, or all four of these muscle-fatiguing issues on a trip out to the trails, one thing for sure is your lactate production is higher than normal. How quickly you can recover from this build-up of lactic acid in your muscles depends on how long it takes your body to flush the lactic acid. Taking the cold plunge does seem to help in aiding your body in this process, but it should be noted that the study in reference indicates alternating hot and cold treatment.
Baths before bedtime
A few months ago I really bumbled on one of my morning rides. I like to rise early, leaving my house with a thermos of hot coffee, and arriving at the trailhead as the sun is coming up. I’m fortunate enough to ride my bike 5-6 days a week, weather permitting, mainly due to my early schedule.
On one particular morning ride, I woke up drowsy from a terrible sleep the night before. For the duration of the ride, my head constantly seemed cloudy and my decision-making felt slow. As you can imagine, this made for an especially scary descent. The terrain is fast, technical, and steep. Hard braking and quick line choice is required nearly the entire way down. Despite having ridden this trail multiple times, I walked sections that I just couldn’t get my head around at that moment. I’m not entirely sure, but I wonder how much my lack of sleep contributed to my struggles that morning.
In a study where endurance runners were tested, those who took the cold plunge did experience better sleep. Twelve well-trained, male endurance runners, with no previous history of using ice baths, participated in the study. Before cold water immersion began, the participants were given sleep-monitoring devices and were asked not to change their sleeping habits. Sleep would be monitored at home, to not disturb regular patterns.
The participants all ran the same course—a simulated trail run on a treadmill that lasted 48 minutes. After the run was over, the participants were tasked with either fully immersing themselves in a cold bath (a snorkel was given), immersing up to their collarbone, or not immersing at all. Their time in the cold water lasted 10 minutes. They would then return home, and follow their regular evening wind-down routine.
Participants’ sleep was monitored during the night and they completed a sleep self-evaluation upon waking. Across the board, the runners who were fully immersed slept better. They tossed and turned less, woke up less at night, and had better slow-wave sleep. What is slow-wave sleep, you may ask? You’ve probably heard it called “deep sleep,” and quality slow-wave sleep is connected to waking up rested and refreshed. Full and partial immersion runners also self-reported feeling more refreshed in the morning.
The psychology of it
Many who have incorporated ice baths into their schedule have not only discussed the physical benefits they’ve received but the mental ones as well: less anxiety and stress, clearer thinking and an overall better mood. This is likely due to increased levels of norepinephrine. Not only does norepinephrine help with alertness and focus, but it also alleviates stress, restricts blood vessels and keeps your blood pressure lower.
Studies have shown that cold water exposure can help with depression. In one particular study, the working theory was that our brains lack the psychological and “thermal exercises” our ancestors experienced. Basically, we no longer have to cross icy rivers to escape predators. These chilly adrenaline rushes helped keep our ancestors alert and their brains functioning normally. Perhaps an icy plunge can help release some of our ancestral chemicals, fending off depression.
Participants, who suffered from depression, were asked to take a cold shower, lasting 2-3 minutes, daily. For some, the treatment lasted several weeks, for others, several months. The chilly waters seemed to work. The sympathetic nervous system was activated and the levels of noradrenaline and beta-endorphins increased.
Not only did researchers see higher levels of hormones being released, but they theorized that cold water on our skin can itself have an anti-depressive effect. Due to our skin’s many cold receptors, contact with cold water can cause increased activity in nerve endings headed to the brain.
The other side…
A simple Google search brings up article after article that agrees with this premise. And not that I don’t trust these publications, but I didn’t see the “scientific method” being followed by a lot of them. In search of perhaps a bit more validity, I found some research published in medical journals and university websites.
That said, for every peer-reviewed study in favor of ice baths, there seemed to be another that was against it. And, even when the studies did boast some benefits, they likely discussed some of the downsides of a cold plunge.
One study showed poorer performance in cyclists who were participating in cold water therapy. This study sought to test the effects of ice baths on maximum power, time duration until peak power output, and heart rate amongst ten high-performance cyclists.
Cyclists performed the same tasks over several days in a controlled environment. On a stationary bike connected to a computer, each participant started with a ten-minute warm-up spin, followed by the cycling task. After the ride was over, the participants either immersed themselves in an ice bath for 15 minutes or were allowed to rest for 15 minutes. After 15 minutes, they were tasked with climbing back on their bike and repeating the cycling regimen.
The results showed that while the time it took for participants to reach their maximum output didn’t change, there was a change in maximum power and heart rate. Both decreased significantly more after the ice bath as compared to the rest period. The study noted that the cyclists not only saw a decrease in performance but would also likely see decreased coordinated movement due to muscle cooling.
It should be noted that while this study demonstrates that the immediate plunge into the cold water wasn’t beneficial to cyclists, it didn’t show if long-term cold water immersion is helpful. Many people have started doing an ice bath as a part of their morning routine. They are not participating in rigorous exercise, taking the plunge, then performing the same exercise. The study may not have real-world crossover in many applications.
Perhaps one of the most damning studies showed that ice baths don’t provide a better recovery than something like a cool-down ride. This study consisted of nine male participants, all around the same level of physical fitness. Each participant completed a single leg workout on two separate days, with cold water immersion or a cool-down routine immediately following.
The leg exercise consisted of a 45-degree leg press, single-leg squats, lunges, and leg extensions. The total time for the exercise was around 45 minutes. After the leg exercise was completed, the participant would then be immersed in cold water to the waist for 10 minutes. They would repeat the same exercise process a week later, but this time an active recovery exercise, riding a stationary bike on low resistance, was completed for 10 minutes instead of a cold plunge.
Researchers took blood from the men’s legs before and immediately after exercise. They followed this by taking blood immediately after, and thirty minutes, one, two, 24, and 48 hours after the ice bath or stationary bike ride. Researchers looked at several different aspects of the participants’ blood work, including creatine kinase levels. Creatine kinase is released into the bloodstream when there is tissue damage, such as an overworked muscle. For example, decreased creatine kinase levels after cold water immersion would show that it aids in muscle recovery.
The bloodwork demonstrated that with an active recovery method, such as the cool-down ride on the stationary bike, the results were very similar, if not the same as when they plunged into the cold bath. So leaving about 10 minutes to pedal around the trailhead parking lot at the end of your ride can save you a chilly dip.
Closing thoughts
The bottom line is to find what works for you. If you experience the psychological benefits of an icy bath, then keep it up. Do you feel like you are more focused and gain confidence on the trails after plunging? Do your thing.
Are you considering starting an ice bath regimen? Check with your doctor and then go for it. Maybe it is beneficial.
Or, you might find that it holds you back. Certainly, the benefits of ice baths aren’t as cut and dry as Instagram or TikTok influencers make them seem.
