Why an icy bath helps athletes keep going strong

On a hot and muggy August morning, thirty-some student-athletes from Temple University, in Philadelphia, were kicking around soccer balls. It was the first practice of the season for the men’s team, and the coach squinted into the hazy heat, evaluating how the players meshed.

After nearly two hours, an athletic trainer for the team, Kendall Stewart, walked away from the field towards a nearby building, to an ice cooler. He loaded a cart with 40-pound bags of ice and wheeled it out front, where a little black stock pool filled with water stood. He cut open the bags and dumped the ice in the tub.

When the players finished practice, they walked over to the pool. They peeled off sweaty shirts and socks and climbed in, yelping from the cold. With the water waist-deep, seven men kneeled in the tub.

What’d it feel like? “A burning sensation until you go numb. Then it feels great,” quipped defender Mark Grasela.

The players rotated through the tub, each spending eight to ten minutes soaking. This low-tech recovery therapy is supposed to help athletes avoid soreness, swelling and fatigue, allowing athletes who practice and compete regularly to be able to go harder more consistently.

An old practice 

Team Captain Matt Mahoney said last year the team didn’t use cold water therapy after every practice because they trained at a faraway facility and didn’t have time. He’s not even positive it works. “I don’t really know,” Mahoney said. “Some people say it doesn’t and some people say it does. I think it works. I think it’s worth doing, I think it’s worth a try.”

Stewart won’t give the team much choice about whether they try it or not. This season, with a new field close to campus, Stewart plans to make a cold soak part of the regular post-practice routine. “If you can stop inflammation at a lower level, if you can get someone’s muscles to relax, and not be overactive, which you would see knots, you would see spasms, and potentially cramping, if I could get all those factors to go away simply by putting someone in an ice tub for eight to 10 minutes, even if it is a little bit uncomfortable,” it’s worth it, he said.

For decades, ice baths have been standard practice for professional and many collegiate athletic programs. Today, some institutions have entire cold rooms for recovery or cold whirlpools, there are chambers that use liquid nitrogen to cool the body, and high-tech pants and gloves that circulate icy water without getting the athlete wet.

No matter the method, the idea is athletes recover quicker, and ultimately perform better. “When you think about it, if they are able to recover better then that next practice they’re able to give it a little bit more and push themselves more, so in that sense, I guess it can enhance your performance,” said Scott Gunter, a New Jersey-based athletic trainer that works with student and professional athletes.

Cold therapy explained 

Although cold therapy has been used for years, nobody knew exactly what was happening in the body to drive that restoration. Dr. Brian Sennett, Chief of Sport Medicine at the University of Pennsylvania, said understanding of the processes is improving.

The primary effects are on the central nervous system, which is the brain, the cardiovascular system, which is the heart, and “it’s also potentially a way to remove breakdown products that build up during exercise,” Sennett said.  

Starting with the central nervous sytem, Sennett said, “there are certain things that get altered in your brain, chemically, with increases in core temperature. Those things include serotonin and dopamine, the same chemicals that can cause depression when not balanced. Changes in the ratio of those chemicals can also increase one’s sense of fatigue. The theory is if an athlete feels like fatigue levels are low, then he or she will perform better.

“Sometimes we ask athletes, ‘How do you feel?’ They say, ‘I feel good today.’ And what does that mean? It means their perception of their energy levels and their fatigue is like optimal. And many times that’s because of what’s going on in the brain, not in their skin, not their muscles, not in the things downstream. It’s really how they feel in their brain,” Sennett said.  

Then there’s the heart.

The heart pumps blood throughout the body, sending more of it to the areas that need it at any given moment. For example, when you’re eating, more blood goes to your stomach, to help digest. And when you’re exercising more blood flows from the core and the organs located there, to the skin and muscles. But when the exercise is over, “we want to drive the fluid and the blood from our skin and that periphery back into the central system,” Sennett said.    

The cold tightens the blood vessels, pushing blood back into the core of the body, and to the heart. With more blood flowing to it, the heart doesn’t have to work as hard, and can start recovering normal operation quicker. 

The final area of recovery is removing exercise induced build-up of things like lactic acid and other potentially harmful molecules. Changes in pressure inside the tissue could help drive them out.

Sennett said the therapy works best for endurance athletes, those that exert the entire body over a significant period of time. 

Even though there’s a better understanding of what’s happening in the body when an athlete takes a cold plunge, there are still no exact guidelines for how to apply cold therapy. There’s no consensus on the temperature that’s most effective, and trainers The Pulse spoke with recommended anywhere between eight and 30 minutes as the optimal amount of time to use the therapy.

“A lot of athletes are superstitious in nature, so they may have a specific ice bath they want to get into, specific temperature, specific amount of time, and then the next day, they had a good game,” Gunter said.  

In other words, like anything in sport, there’s still a bit of hocus pocus involved.