Ice baths are such a widely used method of recovery for athletes that they’ve become a staple in pop culture: Peyton Manning sings insurance jingles in them, and 2014 Boston Marathon winner Meb Keflezighi’s devotion to his post-workout cold soak helped spike interest in the practice.
And why not? Your favorite athletes do it after they train or compete because ice baths are supposed to, among other things, increase circulation to reduce soreness days after your workout, flush out lactic acid, increase metabolism for fat loss and increase testosterone production.
But should you be filling your tub with ice after a hard workout? Elite athletes do, and they rely on many practices backed by sound science. But they also do things that are totally strange -- like wearing energy necklaces and bathing in red wine because they’re superstitious and will do anything they think will make them better, faster, stronger, etc. So are ice baths for real?
Will It Stop Soreness?
When it comes to reducing delayed-onset muscle soreness (DOMS), the condition in which you feel the effects of leg day for the following two days, the studies say no. The idea was that being cold would increase blood flow when you exit the tub, which was supposed to flush bad metabolic debris from your muscles.
But in a small 2013 study of “recreationally active” athletes published in the European Journal of Applied Physiology, a 20-minute dip in a 41-degree (Fahrenheit) ice bath after a workout did not decrease DOMS over a 72-hour period.
Additionally, another study, this one from a 2015 study in BioMed Research International, found that a five-minute ice bath after a 30-minute workout decreased lipid peroxidation, a process that results in cell damage.
Neither study indicated how athletes performed in their next workout, though several other studies have. In a 2007 study, cyclists who soaked for 15 minutes in 55-degree (Fahrenheit) water before returning to the bike saw decreases in power and total work when they hopped back on the pedals after an hour.
But soccer players who soaked in a 50-degree (Fahrenheit) ice bath between games of a tournament felt they were less fatigued and sore, even though physical indicators said that they weren’t any better off than players who didn’t do the ice bath. So the restorative effects of an ice bath may be mostly mental -- and that’s OK.
Will It Burn Fat?
A few years ago, Internet videos and celebrities like Lindsay Lohan were touting the fat-burning and weight-loss benefits of cold showers and ice baths. And unlike many of her career choices, Lohan was on to something.
In a 2014 study from the journal Cell Metabolism, researchers found that shivering for 10 to 15 minutes released the same amount of the hormone irisin that is released during an hour of moderate exercise. Irisin turns white fat cells -- cells that store up to 300 calories of energy -- into brown fat cells, a fat type associated with keeping warm that can burn up to 300 calories per day.
You don’t have to be shivering like crazy, though. The cold experienced by study participants was 14 to 16 degrees Celsius (57 to 60 degrees Fahrenheit), significantly warmer than those in the performance and soreness studies mentioned.
What If It’s Really Cold?
Recently elite athletes have taken post-workout cold therapy to a new extreme, participating in something called “whole-body cryotherapy,” a dry treatment that’s far more frigid (-150 degrees Fahrenheit and colder) and much shorter (about three minutes per session) than traditional ice baths. Athletes -- including Carolina Panthers tight end Greg Olsen, Devin Harris of the Dallas Mavericks and even Lebron James -- have been stepping in these chambers to recover faster.
Studies on this technique tend to be small, and the overall volume of studies is also small, but in some cases this technique has worked. In one study from 2014, active college-age men who underwent whole-body cryotherapy twice a day for five days after a workout significantly reduced the inflammatory response of the exercise when compared with a control group. But at $100 per session, that’s $1,000 just to experience less soreness.
Well, It Can’t Hurt, Right?
Most experts believe that even if the ice baths don’t actually help with the physiological process of recovery, they won’t hurt. And with the perceived effect experienced by soccer players and the fat-converting effects of shivering, this practice may work for your workout recovery.
If you want to try it out, start slow. Note that the best results in the previously mentioned studies were in water that’s cold -- but not ridiculously so. A bath of 50 degrees Fahrenheit gave the soccer players the feeling that they were less fatigued and sore. Start at a warmer temperature like this (or at 57 degrees, as in the fat-converting group), and if you like the experience, gradually decrease the temperature. And if you don’t like it, stop: It may not really work, anyway.